Repair Manual
Engine
WM 80
0162695en
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Copyright
notice
© Copyright 2010 by Wacker Neuson Corporation.
All rights, including copying and distribution rights, are reserved.
This publication may be photocopied by the original purchaser of the machine. Any
other type of reproduction is prohibited without express written permission from
Wacker Neuson Corporation.
Any type of reproduction or distribution not authorized by Wacker Neuson Corporation
represents an infringement of valid copyrights. Violators will be prosecuted.
Trademarks
All trademarks referenced in this manual are the property of their respective owners.
Manufacturer
Wacker Neuson Corporation
N92W15000 Anthony Avenue
Menomonee Falls, WI 53051 U.S.A.
Tel: (262) 255-0500 · Fax: (262) 255-0550 · Tel: (800) 770-0957
www.wackerneuson.com
Foreword
Foreword
Machine
documentation
„
„
„
„
Expectations
for
information in
this manual
„
„
„
Keep a copy of the Operator’s Manual with the machine at all times.
Use the separate Parts Book supplied with the machine to order replacement
parts.
If you are missing any of these documents, please contact Wacker Neuson
Corporation to order a replacement or visit www.wackerneuson.com.
When ordering parts or requesting service information, be prepared to provide
the machine model number, item number, revision number, and serial number.
This manual provides information and procedures to repair the above Wacker
Neuson model(s). For your own safety and to reduce the risk of injury, carefully
read, understand, and observe all instructions described in this manual.
Wacker Neuson Corporation expressly reserves the right to make technical
modifications, even without notice, which improve the performance or safety
standards of its machines.
The information contained in this manual is based on machines manufactured
up until the time of publication. Wacker Neuson Corporation reserves the right
to change any portion of this information without notice.
CALIFORNIA
Proposition
65 Warning
Engine exhaust, some of its constituents, and certain vehicle components, contain
or emit chemicals known to the State of California to cause cancer and birth
defects or other reproductive harm.
Laws
pertaining to
spark
arresters
NOTICE: State Health Safety Codes and Public Resources Codes specify that in
certain locations spark arresters be used on internal combustion engines that use
hydrocarbon fuels. A spark arrester is a device designed to prevent accidental discharge of sparks or flames from the engine exhaust. Spark arresters are qualified
and rated by the United States Forest Service for this purpose. In order to comply
with local laws regarding spark arresters, consult the engine distributor or the local
Health and Safety Administrator.
Manufacturer’s This manual contains references to approved parts, attachments, and modificaapproval
tions. The following definitions apply:
„
Approved parts or attachments are those either manufactured or provided by
Wacker Neuson.
„
Approved modifications are those performed by an authorized Wacker Neuson service center according to written instructions published by Wacker Neuson.
„
Unapproved parts, attachments, and modifications are those that do not
meet the approved criteria.
Unapproved parts, attachments, or modifications may have the following consequences:
„
Serious injury hazards to the operator and persons in the work area
„
Permanent damage to the machine which will not be covered under warranty
Contact your Wacker Neuson dealer immediately if you have questions about
approved or unapproved parts, attachments, or modifications.
wc_tx001528gb.fm
3
Foreword
4
wc_tx001528gb.fm
WM 80
1
Foreword
3
Safety Information
9
1.1
1.2
1.3
1.4
2
14
Engine Specifications ......................................................................... 14
Tune-up Specifications ....................................................................... 15
Carburetor Specifications for Bing, and Tillotson (Standard**) .......... 16
Operating and Idle Speeds ................................................................. 19
Maintenance
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.12
3.13
4
Signal Words Used in this Manual ....................................................... 9
Safety Guidelines for Operating the Machine ..................................... 10
Operator Safety while Using Internal Combustion Engines ............... 12
Service Safety .................................................................................... 13
Technical Data
2.1
2.2
2.3
2.4
3
Table of Contents
20
Periodic Maintenance Schedule ......................................................... 20
Storage ............................................................................................... 21
General Air Filter Maintenance ........................................................... 21
Cartridge-Type Air Filter ..................................................................... 22
Disc-Type Air Filter ............................................................................. 23
Low-Maintenance Air Filter ................................................................. 24
Dual-Element Air Cleaner ................................................................... 25
Three-Stage Air Cleaners ................................................................... 26
Engine Cleaning ................................................................................. 28
Spark Plug .......................................................................................... 28
Muffler ................................................................................................ 28
Fuel Filter ........................................................................................... 30
Fuel Hoses ......................................................................................... 30
Starting and Ignition
4.1
4.2
31
Starter Assembly Exploded View ....................................................... 31
Disassembling the Starter .................................................................. 32
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5
Table of Contents
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11
5
46
Brands Used ........................................................................................46
Walbro Carburetor Operation ..............................................................47
Versions of Tillotson Carburetor ..........................................................54
Tillotson Carburetor Operation ............................................................55
Bing Carburetor Operation ..................................................................61
Carburetor Adapters ............................................................................64
Carburetor Replacement
6.1
6.2
6.3
6.4
6.5
6.6
7
Inspecting the Starter ..........................................................................32
Assembling the Starter ........................................................................33
Replacing the Starter Rope .................................................................34
Ignition System Diagram ...................................................................36
Ignition System Operation ...................................................................37
Checking Spark ...................................................................................38
Using Ignition Tester ...........................................................................39
Setting Air Gap ....................................................................................40
Replacing the Ignition Module .............................................................42
Carburetor Basics
5.1
5.2
5.3
5.4
5.5
5.6
6
WM 80
66
Replacing the Walbro Carburetor (auto-release choke models) .........66
Removing Walbro Carburetor (standard choke models) .....................70
Removal, Tillotson with composite adapter .........................................72
Tillotson with Straight-Through Adapters ............................................74
Tillotson with Elbow Adapters .............................................................74
Bing .....................................................................................................75
Carburetor Overhaul
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
76
Walbro Carburetor Exploded View (auto-release choke models) .......76
Walbro Carburetor Components (auto-release choke models) ...........77
Rebuilding the Walbro Carburetor (auto-release choke models) ........78
Walbro Carburetor Exploded View (standard choke models) .............84
Walbro Carburetor Components (standard choke models) .................85
Rebuilding the Walbro Carburetor (standard choke models) ..............86
Tillotson Carburetor Exploded View ..................................................92
Tillotson Components ..........................................................................93
6
wc_br0162695en_003TOC.fm
WM 80
7.9
7.10
8
Bing Carburetor Exploded View ......................................................... 94
Bing Carburetor Components ............................................................. 95
Carburetor Inspection and Adjustment
8.1
8.2
8.3
9
Table of Contents
Inspection ........................................................................................... 96
Adjusting the Inlet Control Lever ........................................................ 97
Carburetor Adjustments ..................................................................... 98
Carburetor Troubleshooting
9.1
9.2
101
Troubleshooting Walbro Carburetors ............................................... 101
Troubleshooting Tillotson and Bing Carburetors .............................. 102
10 Disassembly and Assembly
10.1
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
10.10
10.11
10.12
10.13
10.14
10.15
10.16
10.17
10.18
10.19
10.20
96
104
Tools ................................................................................................. 104
Special Tools .................................................................................... 104
Ordering Parts .................................................................................. 105
Reference Numbers ( ) ..................................................................... 105
Threadlocking Compounds .............................................................. 105
Removing the WM 80 Engine from BS Rammers (auto-release
choke models) .................................................................................. 106
Removing Engine From BS Model Rammers
(standard choke models) .................................................................. 108
Removing Engine From BH 23 Breakers ......................................... 110
Removing Clutch .............................................................................. 112
WM 80 Exploded View .................................................................... 114
WM 80 Components ......................................................................... 115
WM 80 Cross Section ..................................................................... 116
WM 80 Cross Section Components ................................................. 117
Vacuum Testing Cylinder ................................................................. 118
Cylinder and Piston Removal ........................................................... 120
Cylinder and Piston Inspection ......................................................... 122
Cylinder and Piston Installation ........................................................ 124
Inspecting Connecting Rod and Crankshaft ..................................... 126
Disassembling Crankcase ................................................................ 128
Assembling Crankcase ..................................................................... 130
wc_br0162695en_003TOC.fm
7
Table of Contents
10.21
10.22
WM 80
Crankshaft Bearings ..........................................................................132
Bearing Installation ............................................................................134
8
wc_br0162695en_003TOC.fm
WM 80
1
1.1
Safety Information
Safety Information
Signal Words Used in this Manual
This manual contains DANGER, WARNING, CAUTION, NOTICE, and
NOTE signal words which must be followed to reduce the possibility
of personal injury, damage to the equipment, or improper service.
This is the safety alert symbol. It is used to alert you to potential personal hazards.
f Obey all safety messages that follow this symbol.
DANGER
DANGER indicates a hazardous situation which, if not avoided, will result in death
or serious injury.
f To avoid death or serious injury from this type of hazard, obey all safety messages that
follow this signal word.
WARNING
WARNING indicates a hazardous situation which, if not avoided, could result in
death or serious injury.
f To avoid possible death or serious injury from this type of hazard, obey all safety messages that follow this signal word.
CAUTION!
CAUTION indicates a hazardous situation which, if not avoided, could result in
minor or moderate injury.
f To avoid possible minor or moderate injury from this type of hazard, obey all safety messages that follow this signal word.
NOTICE: Used without the safety alert symbol, NOTICE indicates a
situation which, if not avoided, could result in property damage.
Note: A Note contains additional information important to a procedure.
wc_si000509gb.fm
9
Safety Information
1.2
WM 80
Safety Guidelines for Operating the Machine
Operator qualifications
Only trained personnel are permitted to start, operate, and shut down
the machine. They also must meet the following qualifications:
•
have received instruction on how to properly use the machine
•
are familiar with required safety devices
The machine must not be accessed or operated by:
•
children
•
people impaired by alcohol or drugs
Operator training
Before operating the machine:
•
Read and understand the operating instructions contained in all
manuals delivered with the machine.
•
Familiarize yourself with the location and proper use of all
controls and safety devices.
•
Contact Wacker Neuson Corporation for additional training if
necessary.
When operating this machine:
•
Do not allow improperly trained people to operate the machine.
People operating the machine must be familiar with the potential
risks and hazards associated with it.
Personal Protective Equipment (PPE)
Wear the following Personal Protective Equipment (PPE) while
operating this machine:
•
Close-fitting work clothes that do not hinder movement
•
Safety glasses with side shields
•
Hearing protection
•
Safety-toed footwear
1.2.1
Never operate this machine in applications for which it is not intended.
1.2.2
Do not allow anyone to operate this equipment without proper training.
People operating this equipment must be familiar with the risks and
hazards associated with it.
1.2.3
Do not touch the engine or muffler while the engine is on or
immediately after it has been turned off. These areas get hot and may
cause burns.
1.2.4
Do not operate the machine with unapproved accessories or
attachments.
1.2.5
Never leave the machine running unattended.
10
wc_si000509gb.fm
WM 80
wc_si000509gb.fm
Safety Information
1.2.6
Never tamper with or disable the function of operating controls.
1.2.7
Never use the choke to stop the engine.
1.2.8
Never operate the machine in areas where explosions may occur.
1.2.9
Read, understand, and follow procedures in the Operator’s Manual
before attempting to operate the machine.
1.2.10
Make sure that all other persons are at a safe distance from the
machine. Stop the machine if people step into the working area of the
machine.
1.2.11
Be sure operator is familiar with proper safety precautions and
operation techniques before using machine.
1.2.12
Always keep hands, feet, and loose clothing away from moving parts
of the machine.
1.2.13
Always use common sense and caution when operating the machine.
1.2.14
Always be sure the rammer will not tip over, roll, slide, or fall when not
being operated.
1.2.15
Always turn the engine OFF when the rammer is not being operated.
1.2.16
Always guide the rammer in such a way that the operator is not
squeezed between the rammer and solid objects. Special care is
required when working on uneven ground or when compacting coarse
material. Make sure to stand firmly when operating the machine under
such conditions.
1.2.17
When working near the edges of breaks, pits, slopes, trenches and
platforms, always operate the rammer in such a way that there is no
danger of it tipping over or falling in.
1.2.18
Store the machine properly when it is not being used. The machine
should be stored in a clean, dry location out of the reach of children.
1.2.19
Close fuel valve on engines equipped with one when machine is not
being operated.
1.2.20
Always operate machine with all safety devices and guards in place
and in working order. Do not modify or defeat safety devices. Do not
operate machine if any safety devices or guards are missing or
inoperative.
1.2.21
Do not transport the machine while it is running.
1.2.22
Do not tip the machine for cleaning or for any other reason.
11
Safety Information
1.3
WM 80
Operator Safety while Using Internal Combustion Engines
WARNING
Internal combustion engines present special hazards during operation and fueling. Failure to
follow the warnings and safety standards could result in severe injury or death.
f Read and follow the warning instructions in the engine owner’s manual and the
safety guidelines below.
DANGER
Exhaust gas from the engine contains carbon monoxide, a deadly poison. Exposure to carbon monoxide can kill you in minutes.
f NEVER operate the machine inside an enclosed area, such as a tunnel, unless
adequate ventilation is provided through such items as exhaust fans or hoses.
Operating safety
When running the engine:
•
Keep the area around exhaust pipe free of flammable materials.
•
Check the fuel lines and the fuel tank for leaks and cracks before
starting the engine. Do not run the machine if fuel leaks are present
or the fuel lines are loose.
When running the engine:
•
Do not smoke while operating the machine.
•
Do not run the engine near sparks or open flames.
•
Do not touch the engine or muffler while the engine is running or
immediately after it has been turned off.
•
Do not operate a machine when its fuel cap is loose or missing.
•
Do not start the engine if fuel has spilled or a fuel odor is present.
Move the machine away from the spill and wipe the machine dry
before starting.
Refueling safety
When refueling the engine:
•
Clean up any spilled fuel immediately.
•
Refill the fuel tank in a well-ventilated area.
•
Replace the fuel tank cap after refueling.
•
Do not smoke.
•
Do not refuel a hot or running engine.
•
Do not refuel the engine near sparks or open flames.
12
wc_si000509gb.fm
WM 80
Safety Information
•
1.4
Do not refuel if the machine is positioned in a truck fitted with a
plastic bed liner. Static electricity can ignite the fuel or fuel vapors.
Service Safety
A poorly maintained machine can become a safety hazard! In order
for the machine to operate safely and properly over a long period of
time, periodic maintenance and occasional repairs are necessary.
WARNING
wc_si000509gb.fm
1.4.1
Do not attempt to clean or service the machine while it is running.
Rotating parts can cause severe injury.
1.4.2
DO NOT operate the machine without an air cleaner.
1.4.3
DO NOT remove air cleaner cover, paper element, or precleaner while
engine is running.
1.4.4
DO NOT alter engine speeds. Run the engine only at speeds specified
in the Technical Data Section.
1.4.5
Do not crank a flooded engine with the spark plug removed on
gasoline-powered engines. Fuel trapped in the cylinder will squirt out
the spark plug opening.
1.4.6
Do not test for spark on gasoline-powered engines if the engine is
flooded or the smell of gasoline is present. A stray spark could ignite
the fumes.
1.4.7
Do not use gasoline or other types of fuels or flammable solvents to
clean parts, especially in enclosed areas. Fumes from fuels and
solvents can become explosive.
1.4.8
ALWAYS replace the safety devices and guards after repairs and
maintenance.
1.4.9
Keep the area around the muffler free of debris such as leaves, paper,
cartons, etc. A hot muffler could ignite the debris and start a fire.
1.4.10
ALWAYS do periodic maintenance as recommended in the Operator’s
Manual.
1.4.11
ALWAYS clean debris from engine cooling fins.
1.4.12
Replace worn or damaged components with spare parts designed and
recommended by Wacker Neuson Corporation.
1.4.13
Disconnect the spark plug on machines equipped with gasoline
engines, before servicing, to avoid accidental start-up.
1.4.14
Keep the machine clean and labels legible. Replace all missing and
hard-to-read labels. Labels provide important operating instructions
and warn of dangers and hazards.
13
Technical Data
2
WM 80 Repair
Technical Data
2.1
Engine Specifications
Engine Model
WM 80
Type
2-cycle
Maximum rated power
(kW) hp
3.0 (4.0)
Number of cylinders
Piston displacement
1
cc
(cu.in.)
80 (4.9)
Cylinder bore
mm (in.)
(45) 1.77
Stroke
mm (in.)
50 (1.96)
Compression ratio
Operating speed range
9:1
rpm
3,000–5,000
Starter
Pull-type, recoil starter
Ignition
Transistor-controlled electronic (TCI)
Carburetor
Diaphragm
Fuel
Gas/oil mixture
Fuel:oil ratio
between 120–50:1 (first tank 25:1)
Cooling
Weight
Direction of rotation
Forced air
kg (lbs.)
7.8 (17)
Counterclockwise when viewed from drive end
14
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WM 80 Repair
2.2
Technical Data
Tune-up Specifications
Engine Model
WM 80
Ring gap:
New
Maximum
mm (in.)
mm (in.)
0.2–0.4 (0.008–0.016)
1.0–1.2 (0.039–0.047)
Cylinder wear:
Maximum bore taper
mm (in.)
0.2 (0.008)
Cylinder head
compression
kg/cc (psi)
8.0–9.7 (120–140)
Ignition module air gap*
mm (in.)
0.4 (0.016)
Spark plug gap:
Champion RL86C
Champion UJ11G
Champion RL95YC**
mm (in.)
mm (in.)
mm (in.)
0.5 (0.020)
1.0–1.1 (0.040–0.045)
0.5 (0.020)
* On models with adjustable air gap
** Must be used on models with oil injection
wc_td000166gb.fm
15
Technical Data
2.3
WM 80 Repair
Carburetor Specifications for Bing, and Tillotson (Standard**)
Machine
Carburetor
Make
Low-speed jet
size (x 0.01)
High-speed jet
size (x 0.01)
Carburetor
adapter bore
diameter
mm (in.)
BS 45Y
•Bing
•Tillotson
•Tillotson w/
idle bypass
#35
Adjustable
#62
#71*
8 (0.315)
8 (0.315)
#36
#70
8 (0.315)
BS 50
Bing
#40
#64
12 (0.472)
BS 52Y
•Bing
•Tillotson
•Tillotson w/
idle bypass
#35
Adjustable
#62
#71*
9 (0.354)
9 (0.354)
#36
#70
9 (0.354)
•Bing
•Tillotson
•Tillotson w/
idle bypass
#35
Adjustable
#62
#71*
12 (0.472)
11 (0.433)
#36
#70
11 (0.433)
•Bing
•Tillotson
•Tillotson w/
idle bypass
#35
Adjustable
#62
#71*
12 (0.472)
14 (0.551)
#36
#70
14 (0.551)
BS 65Y
#35
#62
16 (0.630)
BS 100Y
#40
#64
16 (0.630)
#40
#58
10 (0.394)
#40
#58
10 (0.394)
BVNPN
#40
#64
12 (0.472)
BHF 30S
#40
#58
16 (0.630)
#42
#74
10 (0.394)
#36
#78
13 (0.512)
#36
#66
13 (0.512)
BS 60Y
BS 62Y
BPS 1330
BPS 1350
BH 23
BS 500 7550
Rev. 100–102
BS 500 7550
Rev. 103–110
Bing
Tillotson w/ idle
bypass
Tillotson w/ idle
bypass
16
wc_td000166gb.fm
WM 80 Repair
Technical Data
BS 500 7550
Rev. 111–121
#36
#70
13 (0.512)
BS 500 7550
Rev. >121
#36
#70
11 (0.433)
BS 500 8048
Rev. 100–102
#36
#78
13 (0.512)
BS 500 8048
Rev. 103–110
#36
#66
13 (0.512)
BS 500 8048
Rev. 111–118
#36
#70
13 (0.512)
BS 500 8048
Rev. >118
#36
#70
11 (0.433)
BS 500 8049
Rev. 100–102
#36
#78
13 (0.512)
BS 500 8049
Rev. 103–110
#36
#66
13 (0.512)
#36
#70
13 (0.512)
BS 500 8049
Rev. >120
#36
#70
11 (0.433)
BS 500 9074
High Altitude
Rev. 116
#36
#70
16 (0.630)
BS 500oi 9166
#36
#72
11 (0.433)
BS 600 7551
Rev. 100–103
#36
#78
14 (0.551)
BS 600 7551
Rev. 105–120
#36
#66
13 (0.512)
BS 600 7551
Rev. >121
#36
#72
13 (0.512)
BS 600 8207
High Altitude
Rev. <104
#36
#78
16 (0.630)
BS 500 8049
Rev. 111–119
wc_td000166gb.fm
Tillotson w/ idle
bypass
17
Technical Data
WM 80 Repair
BS 600 8207
High Altitude
Rev. > 104
#36
#74
18 (0.709)
BS 600oi 9166
#36
#72
18 (0.709)
BS 600oi 9262
High Altitude
#36
#74
18 (0.709)
BS 700 7552
Rev. <104
#36
#78
16 (0.630)
BS 700 7552
Rev. 104–118
#36
#74
18 (0.709)
BS 700 7552
Rev. >118
#36
#74
18 (0.709)
BS 700 8051
Rev. 100–120
#36
#78
16 (0.630)
BS 700 8051
Rev. >120
#36
#74
16 (0.630)
#36
#78
16 (0.630)
BS 700 8052
Rev. 103–118
#36
#74
18 (0.709)
BS 700 8052
Rev. >118
#36
#74
18 (0.709)
BS 700oi 9167
#36
#74
18 (0.709)
BS 50-2 9384
#36
#72
19 (0.748)
BS 50-2i 9338
#36
#72
19 (0.748)
BS 50-2i 9383
#36
#72
19 (0.748)
BS 60-2i 9339
#36
#72
19 (0.748)
BS 60-2i 9393
#36
#72
19 (0.748)
BS 70-2i 9341
#36
#72
19 (0.748)
BS 70-2i 9401
#36
#72
19 (0.748)
BS 700 8052
Rev. 100–102
Tillotson w/ idle
bypass
* Single-needle Tillotson carburetors only. Dual-needle Tillotson carburetors use an adjustable needle
for high-speed adjustment.
** Standard sizes listed. Operation at altitudes above 3000 m (5000 feet) may require different jet and
carburetor adapter sizes. Contact Wacker Neuson Neuson Service for the modifications required.
18
wc_td000166gb.fm
WM 80 Repair
2.4
Technical Data
Operating and Idle Speeds
Machine
Idle speed ±100 rpm
Full speed ±100 rpm
BS 45Y
1800
4300
BS 52Y
1800
4300
BS 60Y
1800
4600
BS 62Y
1800
4500
BS 65Y
1500
4400
BS 100Y
1500
4300
BS 105Y/92Y
1500
4400
BPS 1330
1500
4800
BPS 1350
1500
4800
BVNPN
1700
4500
BHF 30S
1500
4300
BH 23
1500
4250
BS 500
1800
4400
BS 500-oi
1800
4400
BS 50-2
1800
4400
BS 50-2i
1800
4400
BS 600
1800
4350
BS 600-oi
1800
4350
BS 60-2
1800
4350
BS 60-2i
1800
4350
BS 650
1800
4350
BS 65V
1800
4350
BS 700
1800
4350
BS 700-oi
1800
4350
BS 70-2
1800
4350
BS 70-2i
1800
4350
wc_td000166gb.fm
19
Maintenance
3
WM 80
Maintenance
3.1
Periodic Maintenance Schedule
Daily
After first
5 hours
Every
week or
25 Hours
Check & tighten engine cylinder screws.
•
•
Check & tighten external fasteners.
•
•
Clean and check spark plug gap.
•
•
Check fuel level.
•
Clean and/or inspect air filter (cartridge type).
•
Clean and oil foam precleaner where equipped.
•
Check condition of fuel lines.
•
Clean engine cooling fins.
Every
month or
100 Hours
Every 3
months or
300 hours
•
Replace cartridge style air filter element.
•
Replace spark plug.
•
Clean recoil starter.
•
Remove carbon deposits from muffler & cylinder
exhaust port.
•
Replace in-line fuel filter.
•
Inspect in-tank fuel filter.
•
20
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WM 80
3.2
Maintenance
Storage
If storing the unit for a long period of time (more than 30 days) carry
out the following:
3.3
3.2.1
Drain fuel from the tank.
3.2.2
Start the engine and run it until all the fuel in the carburetor is used.
3.2.3
Remove the spark plug and pour 30 ml (1 oz.) of clean SAE 30W
engine oil into the cylinder through the spark plug opening.
3.2.4
Pull the starter rope slowly to distribute oil in the engine.
3.2.5
Reinstall the spark plug.
General Air Filter Maintenance
Inspect the air filter daily. Severe damage to the engine components
can occur if the engine is operated with a damaged element. This is
especially important when operating in extremely dusty conditions; dirt
and sand, if allowed to enter the engine, can quickly destroy the
cylinder wall and piston.
NOTICE: Never operate the engine without an air filter. Damage to the
engine will occur.
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21
Maintenance
3.4
WM 80
Cartridge-Type Air Filter
See Graphic: wc_gr002875
3.4.1
This type of air filter is found on rammers with Bing carburetors and on
early rammers with Tillotson carburetors. To service:
3.4.2
Unsnap the spring clips (1) on the protective cover (2) and remove the
filter element (3).
3.4.3
Inspect the paper filter element and replace it if it appears wet, heavily
soiled, or torn.
3.4.4
Inspect the condition of the rubber seals (4) on each end of the
element. Replace the element if the seals are damaged or deformed.
3.4.5
The element can be cleaned by tapping it against a firm surface. Take
care not to damage the seals or puncture the filter paper when
cleaning the filter. Do not use cleaning agents or solvents to clean the
filter.
3.4.6
Clean and inspect the seating surfaces on the mounting base (5) and
inside of the protective cover. Replace any damaged parts. Lightly oil
filter the seals and install the element.
2
3
4
1
5
wc_gr002875
22
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WM 80
3.5
Maintenance
Disc-Type Air Filter
See Graphic: wc_gr002876
The disc-type air filter with oil-wetted foam precleaner is used on BPS
1330, BPS 1350, BVPN 50, and the BHF 30S. To service the filter:
3.5.1
Close the carburetor choke. Loosen the clamp (1) around the
carburetor and remove the precleaner housing (2).
3.5.2
Remove the metal screen (3) from the carburetor and inspect it.
Replace the screen if it is heavily soiled or damaged. The screen can
be cleaned by tapping it against a firm surface or by using lowpressure (30 psi) compressed air.
3.5.3
Remove the retainer (4) and the foam precleaner (5) from the housing
and inspect. Replace the precleaner if it appears heavily soiled or
damaged. The precleaner can be cleaned by using a mild detergent
and warm water. Rinse it thoroughly and dry it with a lint-free cloth.
3.5.4
After cleaning, soak the precleaner in clean engine oil (SAE 30W),
squeeze out excess oil, and reinstall the filter.
3
2
1
5
4
wc_gr002876
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23
Maintenance
3.6
WM 80
Low-Maintenance Air Filter
See Graphic: wc_gr002877
This type of air filter is found on rammers. The air filter is self-cleaning
and uses the movement of the machine to shake dust and dirt loose
from the air filter element while the rammer is operating. Under normal
operating conditions this element will not require cleaning and should
not be removed from the machine. If the element does become
plugged with dirt, the engine will begin to lose power. In this case, the
air filter element can be removed and cleaned as described below.
Replace the element if it becomes so plugged with dirt it can no longer
be cleaned.
3.6.1
Remove the two locknuts from the top of the air filter and lift the air filter
off.
3.6.2
Use compressed air directed from the inside of the air filter, through the
grommet hole (1), to blow dirt and dust from the element.
NOTICE: Air pressure must not exceed 100 psi.
3.6.3
Run fresh water through the grommet hole (1) until water runs clear
NOTICE: DO NOT use solvents, fuel oil, or gasoline to wash the filter.
3.6.4
Plug or cover the hole in the air filter (2) using a cork or tape to prevent
dirty water from entering inside the element. Soak the air filter in a
solution (3) of warm water and a low-suds detergent for at least 15
minutes. Longer periods of time (up to several hours) of soaking may
be required, depending on how dirty the element is.
3.6.5
Remove the air filter from the water and repeat rinsing the filter as
described in Step 3. Allow the element to air dry in a dust-free area.
DO NOT use heat to speed drying.
3.6.6
Inspect the grommet before assembly and replace it if it is worn or
damaged. Install the grommet on the element carefully to avoid cutting
it.
3.6.7
Install the air filter on the machine and secure it with washers and
locknuts. DO NOT overtighten. Overtightening can deform washers
and indent the top of the air filter.
Note: Apply grease or liquid soap to inside of grommet so it slides
easily on machine.
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Maintenance
1
2
3
wc_gr002877
3.7
Dual-Element Air Cleaner
See Graphic: wc_gr000046
NEVER use gasoline or other types of low flash-point solvents for
cleaning the air cleaner. A fire or explosion could result.
WARNING
NOTICE: NEVER run engine without air cleaner. Severe engine
damage will occur.
The rammer is equipped with a dual-element air cleaner. Under normal
operating conditions, elements should be cleaned once every week.
Under severe, dry and dusty conditions, the elements should be
maintained daily. Replace an element when saturated with dirt that
cannot be removed. Clean elements using the following procedure:
3.7.1
Remove air cleaner cover (a). Remove precleaner and paper element
and inspect them for holes or tears. Replace if damaged.
3.7.2
Precleaner (b): Clean with low-pressure compressed air. When very
soiled, wash in solution of mild detergent and warm water. Rinse
thoroughly in clean water. Allow to dry thoroughly before re-installing.
Note: Do not oil precleaner.
3.7.3
Paper element (c): Tap element lightly to remove excess dirt. Replace
paper element if it appears heavily soiled.
3.7.4
Wipe out filter housing (d) with a clean cloth.
NOTICE: Do not allow dirt to get into the engine intake port while
cleaning—damage to the engine will result.
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25
Maintenance
3.8
WM 80
Three-Stage Air Cleaners
See Graphic: wc_gr001168
NEVER use gasoline or other types of low flash point solvents for
cleaning the air filter. A fire or explosion could result.
WARNING
NOTICE: NEVER run engine without main paper filter element (b).
Severe engine damage will occur.
Filter Indicator
The air intake system is equipped with a filter indicator (h), which
indicates when a filter change is required. Replace the main paper filter
element (b) when the yellow plunger of the indicator appears in or near
the red line. Push and hold in the yellow plunger on top of the indicator
to reset it after replacing the main paper filter element.
Clean elements using the following procedure:
3.8.1
Remove the air cleaner cover (a). Remove the main paper filter
element (b) and the secondary prefilter (c) and inspect them for holes
or tears. Replace the elements if they are damaged.
3.8.2
Main paper filter element (b): Replace the main paper filter element if
it appears heavily soiled and/or when the yellow plunger of indicator
appears in or near the red line.
3.8.3
Prefilter (c): Clean it with low-pressure compressed air. When the
prefilter is very soiled, wash it in a solution of mild detergent and warm
water. Rinse it thoroughly in clean water. Allow the prefilter to dry
thoroughly before reinstalling it.
Note: Do not oil the prefilter.
3.8.4
Wipe out the filter housing (d) with a clean cloth. Do not use
compressed air.
NOTICE: Do not allow dirt to get into the engine intake port (k) while
cleaning. Damage to engine will result.
3.8.5
Check that the precleaner debris ejector slot (i) is clear.
26
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WM 80
Maintenance
a
b
c
i
d
h
k
wc_tx000520gb.fm
wc_gr001168
27
Maintenance
3.9
WM 80
Engine Cleaning
The WACKER WM 80 engine is air cooled and depends on the
cylinder cooling fins to dissipate heat. Dirt and debris caught in the
cooling fins can prevent them from dissipating heat causing the engine
to overheat. For this reason, it is important to inspect and clean the fins
as often as job conditions dictate. Clean debris from between the fins
using a screwdriver or similar implement.
3.10 Spark Plug
A well-maintained spark plug is essential to good combustion. Keep
the spark plug’s electrode clean and gapped to the correct setting. See
section Tune-up Specifications. Before removing the spark plug from
the engine, clean the immediate area around the spark plug to prevent
any dirt from falling into the cylinder when the spark plug is removed.
NOTICE: Do not remove the spark plug while the engine is hot. The
aluminum threads of the cylinder may strip.
3.11 Muffler
See Graphic: wc_gr005088, wc_gr007375
Carbon deposits normally form over a period of time at the engine
exhaust and the muffler. If allowed to accumulate, these deposits may
eventually restrict the exhaust passages, resulting in poor
performance and hard starting. Factors contributing to excessive
carbon buildup include:
•
Too much oil in the fuel mixture
•
Dirty air filter
•
Excessive idling
•
Dirty carburetor
•
Too rich fuel/air mixture
•
Incorrect fuel jets
To service the muffler:
3.11.1 Remove the muffler (1, 2) from the engine.
3.11.2 Crank the engine until the piston is at the top of its stroke and covering
the exhaust port.
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Maintenance
3.11.3
Clean the exhaust port using a blunt scraper. Inspect the gasket (3, 4)
and replace it if torn or cracked.
3.11.4
Soak the muffler in carburetor cleaner until the carbon deposits break
up. Drain the muffler and blow dry it dry with compressed air.
29
Maintenance
WM 80
3.12 Fuel Filter
See Graphic: wc_gr002879
Dirt is the primary cause of carburetor problems. Unfiltered fuel can
quickly plug the passages in the carburetor and cause poor
performance. Two different styles of fuel filters are used with the WM
80 engine. One is an in-tank, self-cleaning style (h), the other is an inline replaceable filter (i). No matter the style, it is imperative the fuel
filter be clean. Check in-line fuel filters often and replace at regular
intervals. Check in-tank fuel filters yearly. Clean the filter by back
flushing with solvent. Replace the fuel filter if necessary. See section
Periodic Maintenance Schedule.
h
i
wc_gr002879
3.13 Fuel Hoses
WARNING
Check the condition of the fuel hoses frequently and make sure they
are adequately clamped at the tanks and the filters.
Use extreme caution when working on the fuel system. Do not spill fuel
on yourself or others. Clean up any spilled fuel. See section Engine
Safety.
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4
Starting and Ignition
Starting and Ignition
4.1
Starter Assembly Exploded View
1
4
5
6
13
9
7
10
8
3
11
2
12
wc_gr002880
See Graphic: wc_gr002880
Ref
Description
Ref
Description
1
Starter assembly
8
Spring
2
Rope
9
Ratchet wheel
3
Handle
10
Cover
4
Wear plate
11
Lock washer
5
Return spring
12
Locknut
6
Starter pulley
13
Starter housing
7
Washer
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31
--
Starting and Ignition
4.2
WM 80 repair
Disassembling the Starter
See Graphic: wc_gr002880
4.3
4.2.1
Remove the starter assembly from the fan cover and release the
spring tension as described in section Replacing the Starter Rope.
4.2.2
Untie the rope (2) and remove the handle (3).
4.2.3
Remove the locknut (12), lock washer (11), and cover (10).
4.2.4
Remove the ratchet (9), spring (8), and washer (7). Note the position
of the ratchet and the spring to ensure proper reassembly.
4.2.5
Slowly lift the rope reel pulley (6) from the starter housing (13). Also
remove the wear plate (4). If necessary, carefully remove the spring (5)
from the rope reel pulley.
Inspecting the Starter
See Graphic: wc_gr002881
Starter Return Spring
Replace the starter return spring if it is broken, or appears distorted or
twisted. Check that the starter return spring ends are bent 180° (a). The
starter return spring may be difficult to seat in the slots on the starter
housing and the rope reel pulley, if the return spring ends are stretched
out (b) or damaged.
Rope Reel Pulley
Inspect the rope reel pulley for wear in the area where the starter return
spring makes contact. Remove any dirt and grease from between the
spring windings. Slip the rope reel pulley over the center post in the
housing and check its movement. The rope reel pulley should rotate
freely on the post with a minimum amount of side play.
Ratchet
Check the ratchet tooth for wear. The tip (c) should be pointed, not
rounded. A worn ratchet may slip when engaging the flywheel.
Replace the ratchet when it is worn.
Rope
Check the rope length. It is 150 cm (60 in.) when new. If the rope is too
short, it may bottom out when pulled and damage the starter.
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Starting and Ignition
b
a
d
e
c
f
wc_gr002881
4.4
Assembling the Starter
See Graphic: wc_gr002880 and wc_gr002881
4.4.1
Clean all the components of the starter before reassembling the
starter.
4.4.2
Note: To reduce dirt and dust from collecting between the spring
windings, avoid using grease to lubricate the tarter return spring or the
inside of the reel where the spring seats. Use a light lubricating oil such
as WD40 instead.
4.4.3
Install the spring (e)(5) by placing the outside end of the spring in the
slot (d) on the rope reel pulley (f) (6). Wrap the spring in a
counterclockwise direction inside the pulley until it is completely
wound. Oil the spring lightly once it is wound.
4.4.4
Lightly grease the center post of the housing and install the wear plate
(4) and the rope reel pulley. Rotate the rope reel pulley until the spring
seats in the slot at the center of the housing (13). Install the washer (7)
over the center post and seat it into the rope reel pulley.
NOTICE: Failure to replace the washer will cause the ratchet to bind
and prevent the rope reel pulley from rotating freely.
wc_tx000521gb.fm
4.4.5
Add the spring (8) and the ratchet (9) to the assembly. Do not grease
the ratchet.
4.4.6
Install the cover (10) and secure it in place using the lock washer (11)
and locknut (12). Torque the locknut to 8 Nm (6 ft.lbs.). Install the rope
as described in section Starter Rope Replacement.
33
Starting and Ignition
4.5
WM 80 repair
Replacing the Starter Rope
See Graphic: wc_gr002882
The starter rope can be replaced without removing the rope reel pulley
from the starter assembly.
Removal:
4.5.1
Remove the starter assembly from the flywheel housing.
4.5.2
Lift the rope through the notch (a) in the drum. Pull out as much of the
rope as possible. Hold the rope and let the spring pull the drum around
clockwise until all spring tension is released.
4.5.3
Untie the knot and remove the rope.
Installation:
4.5.4
Thread the new rope through the rope reel pulley and then through the
housing. Install the handle and knot (b) each end of the rope as shown.
Be sure the end of the rope does not protrude from the rope reel (c) or
it may interfere with the movement of the starter.
4.5.5
Lift the rope up through the notch in the edge of the drum and rotate
the drum counterclockwise to wind the spring. Guide (d) the rope
around as the drum is rotated. After two complete revolutions, remove
the rope from the notch and allow it to be pulled around the drum by
the spring tension (e). Repeat this procedure until all the rope is on the
drum and the handle rests against the housing.
4.5.6
Reattach the starter assembly to the flywheel housing.
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Starting and Ignition
a
b
c
d
e
wc_gr002882
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35
Starting and Ignition
4.6
WM 80 repair
Ignition System Diagram
c
d
a
S
b
N
f
e
aa
aaa
g
wc_gr002883
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4.7
Starting and Ignition
Ignition System Operation
See Graphic: wc_gr002883
The ignition system consists of the ignition module (a), flywheel (b),
shutoff switch (c) or (d), and spark plug (e).
During each engine revolution, a permanent magnet (f) embedded in
the flywheel passes under the ignition module. As the magnet passes
the module, it induces a current in the primary side of the coil. After it
passes, the triggering circuit is activated and the current flow to the coil
is interrupted. The resulting collapse of the magnetic field around the
coil secondary causes a voltage discharge to fire the spark plug.
Older Ignition Systems
Spark is provided by a breakerless electronic Transistor Controlled
Ignition (TCI). There are no breaker points or capacitors. The ignition
module is completely self-contained and fully enclosed. It includes the
ignition coil and triggering circuit. Two different modules are used. The
standard module (aa) is used in all applications except for rammer
models BS62Y and BS65Y. On these models an ignition module (aaa)
with speed limiter is used. This module cuts out ignition pulses at
higher speeds to keep the engine from running away. The two modules
are not interchangeable. Note the physical differences as shown. The
speed limiting module has an extra coil (g) and a yellow ground wire.
The standard module has no extra coil and a blue ground wire.
NOTICE: Do not use the standard module on the BS62Y or the BS65Y
rammers. Engine damage will occur.
Newer Ignition Systems
Starting with Rammer Models BS 500 and BS 600 (including models
with oil-injection) and carrying through to current Rammer Models BS
50-2 and BS 60-2 (also including models with oil-injection) a
microprocessor-based ignition system is used. This retarding-type.
ignition alters the timing (advance or retard) of the spark to match the
load.
Two different styles of engine shutoff switches are used. One is a stop
switch (c) located on the engine housing (breakers, plates). The other
is a fuel/shutoff switch (d) located under the fuel tank (rammers). This
switch cuts power to the engine and closes the fuel valve. Both styles
of shutoff switches are normally open and when activated create a
short circuit directly to ground. The short circuit prevents the plug from
firing and thus stops the engine.
wc_tx000521gb.fm
37
Starting and Ignition
4.8
WM 80 repair
Checking Spark
Remove the spark plug and inspect the electrode and insulator for
damage. Also check electrode for proper gap. See section Tune-up
Specifications. Return the spark plug to the cylinder before checking
for spark.
WARNING
WARNING
Do not check for spark with the spark plug removed. Fuel could squirt
out of the spark plug opening.
Do not touch or lean against the engine when checking for spark.
Touching or leaning against engine when checking spark can result in
electric shock.
Do not check for spark near flammable gases, liquids, or materials.
The spark may ignite them.
WARNING
4.8.1
To check for spark, carry out the following procedures:
4.8.2
Unscrew the cap from the end of the ignition cable and insert a short
length of stiff, bare wire into the cable and allow it to extend slightly
from the end.
4.8.3
Hold the ignition cable with the bare wire approximately 3 mm (1/8inch) from the engine cylinder and pull the rope on the rewind starter.
4.8.4
If a strong blue spark is observed, the ignition module is satisfactory
and either the spark plug or the connection in the cap is faulty.
4.8.5
If no spark is observed, remove the engine hood and disconnect the
wire from the stop switch. Also check the air gap in module. Check for
spark in same manner as before. Make sure the ground wire does not
touch the engine.
4.8.6
If spark occurs with switch disconnected, the switch is defective. If
spark is still not present, the ignition module or wires are faulty.
Note: Checking for spark does not always provide a reliable test of the
ignition system. A weak ignition module may generate sufficient
voltage to fire the plug when removed from the cylinder but not enough
when it is under compression in the cylinder.
Lack of spark may not be the result of a faulty ignition module. Before
replacing the ignition module, check for:
•
Bad or fouled spark plug
•
Metal connector in spark plug cap corroded or broken
•
Broken, frayed, or shorted ignition wire or ground lead
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4.9
Starting and Ignition
•
Poor wire connections
•
Defective stop switch
•
Incorrect air gap
•
Weak or dead flywheel magnet
•
Insufficient rpm (must have 500 min.)
Using Ignition Tester
See Graphic: wc_gr002884
A more accurate test of the ignition module can be made using ignition
tester P/N 78836 (a).
4.9.1
Preset gap to 4.2 mm (0.166 in.) (b).
4.9.2
Attach the end of the ignition cable to one end of the tester. Ground the
other end of the tester by clipping it onto the engine cylinder. Crank the
engine using the rewind starter or by spinning the flywheel. If a spark
jumps the test gap, the ignition system is operating satisfactorily.
Note: A minimum of 500 rpm is required to produce spark.
b
a
wc_gr002884
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Starting and Ignition
WM 80 repair
4.10 Setting Air Gap
See Graphic: wc_gr002885
Newer engines use guide sleeve pins to automatically set the air gap;
however, older models still require the proper air gap to be set
manually. If the air gap is set incorrectly, the engine may be hard to
start or it may run erratically. Check the air gap (a) with a feeler gauge
and if the gap is not set at 0.4 mm (0.013–0.016 in.) the air gap needs
to be reset.
To set the air gap:
4.10.1 Loosen the three screws (b) holding the ignition module (c) to the
crankcase.
4.10.2 Rotate the flywheel until the magnet (d) is positioned directly under the
module.
4.10.3 Insert a feeler gauge between the module and the flywheel and move
the module until the correct gap is set. Torque the screws to 3.5 Nm
(2.5 ft.lbs.).
NOTICE: Do not overtighten the screws on the module or the threads
in the engine housing may be damaged.
40
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Starting and Ignition
b
c
S
N
d
a
wc_gr002885
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41
Starting and Ignition
WM 80 repair
4.11 Replacing the Ignition Module
See Graphic: wc_gr002886
Removal:
The engine does not have to be removed from the machine to replace
the ignition module.
4.11.1 Disconnect the ignition wire from the spark plug.
4.11.2 Remove the seven M5 screws (a) which secure the flywheel housing
to the crankcase. Note: The screws may require heat to loosen.
Separate the flywheel housing from the crankcase.
4.11.3 When removing the M12 nut (b), it is recommended that an impact
wrench be used. An alternative is to insert a screwdriver (c) into one of
the two holes in the starter cup to prevent the flywheel from turning.
Then, use a 19 mm socket and turn the M12 nut counterclockwise to
remove it from the crankshaft. Also remove the washer under the M12
nut.
4.11.4 Thread flywheel puller P/N 46503 (d) completely onto the threaded
shaft of the flywheel. Turn the pusher screw portion of the puller until it
engages with the crankshaft. Continue turning the pusher screw until
the flywheel is free from the tapered shaft of the crankshaft. Note: The
flywheel may “pop” at the moment it is free from the crankshaft.
Remove the flywheel puller and remove the flywheel.
4.11.5 Remove the key from the crankshaft.
4.11.6 Remove the screws (e) which secure the ignition module (f) to the
crankcase.
4.11.7 Bend the retaining tab (g) to allow the ignition wire to be removed from
the housing.
4.11.8 Remove the sticker (h) which keeps the wires in the groove of the
flywheel housing.
4.11.9 Loosen the screw (i) which secures the ground wire to the stop switch
and remove the ground wire (j) from the stop switch. Then, pull the
ground wire through the wire harness.
4.11.10 Unscrew the ignition wire (k) from the ignition module and remove the
ignition module.
4.11.11 Pull the ignition wire from the crankcase.
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Starting and Ignition
b
a
d
c
f
i
h
j
g
k
e
f
wc_gr002886
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43
Starting and Ignition
WM 80 repair
See Graphic: wc_gr002887
Installation:
4.11.12 Apply a light coating of oil to the ground (a) and ignition wires (b) and
slide them through the protective sleeve (c).
4.11.13 Slide the ignition wire through the boot (d) in the side of the crankcase.
4.11.14 Secure the ground wire to the stop switch (e). (Older models use a
terminal flag (f).) Tuck the ground wire within the groove of the
crankcase.
4.11.15 Position the wire sleeve underneath the holding tab (g) and bend the
tab down to hold the wires and sleeve in place.
4.11.16 Clean the area of the crankcase around the ground wire and apply a
new white label (h) to the crankcase.
4.11.17 Attach the spark plug cap (i) to the ignition wire.
4.11.18 Apply Loctite 243 or equivalent to three M8 slot head screws (j) and
using the screws, secure the ignition module (k) to the crankcase.
Torque screws to 3.4 Nm (2.5 ft.lbs.). For those engines requiring
manual air gap adjustment, adjust the ignition module air gap. See
section Setting Air Gap.
4.11.19 Insert the key into the crankshaft. Secure the flywheel (l) to the
crankshaft with washer and M12 nut (m). Torque the nut to 50 Nm (41
ft.lbs.).
4.11.20 Check for spark. See section Checking Spark.
4.11.21 Apply Loctite 243 or equivalent to seven M5 screws (n) and using the
screws, secure the flywheel housing to the crankcase.
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Starting and Ignition
b
j
k
c
a
d
b
e
f
h
g
i
m
l
o
n
wc_gr002887
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Carburetor Basics
5
WM 80 Repair
Carburetor Basics
5.1
Brands Used
See Graphic: wc_gr005089
Three brands of carburetors are used on the WM 80 engine: Walbro
(1), Tillotson (2), and Bing (3).
The Walbro and Tillotson carburetors have internal fuel pumps while
the Bing uses gravity feed to supply the fuel from the tank to the
engine. With the Bing carburetor, the fuel tank must be located above
the carburetor for the fuel feed to work properly. The fuel pumps on
Walbro and Tillotson carburetors operate on differences in air pressure
between the atmosphere and the crankcase. No matter the design, the
carburetors can be used at different angles and are very tolerant of
high vibration.
As of the publishing of this manual, only one version of the Walbro
carburetor has been used. It is a fixed jet design. It features an air
purge system.
Three different versions of the Tillotson carburetor have been used:
Dual Needle, Single Needle, and Fixed Jets With Primary Idle Bypass.
See section Tillotson Carburetor Versions.
Two different versions of the Bing carburetor have been used: one with
a metal inlet control lever and a plastic choke, and another with a fixed
plastic inlet control lever and a metal choke.
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5.2
Carburetor Basics
Walbro Carburetor Operation
Fuel Pump
The fuel pump is made up of a diaphragm (a) and a series of check
valves (b & c). The power to operate the fuel pump comes from the
crankcase impulse.
As the engine’s piston moves up into the cylinder it creates a lowpressure area in the crankcase. The vacuum pulse travels through the
impulse passage and draws up on the pump diaphragm creating a
vacuum within the fuel chamber. Atmosphere pressure in the fuel tank
pushes the fuel through the fuel filter and fuel line. The vacuum opens
the inlet check valve (b) and allows fuel to fill the fuel chamber. The
vacuum also closes the outlet check valve (c).
As the piston moves down into the crankcase it pressurizes the air.
The pressurized air travels through the impulse passage into the
carburetor fuel pump. It pushes on the diaphragm pressurizing the fuel.
The pressurized fuel closes inlet check valve opens the outlet check
valve. Fuel flows to the inlet screen and to the inlet needle and the fuel
metering system.
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Carburetor Basics
WM 80 Repair
Fuel Metering
There are four components of the fuel metering system: the metering
diaphragm (a), the metering lever (b), the spring (c), and the inlet
needle (d).
The metering lever transfers the pressure of the spring to the inlet
needle, holding the inlet needle closed and preventing fuel flow. When
the metering diaphragm senses a vacuum pulse from the engine, it
moves inward toward the carburetor. This action moves the metering
lever, which in turn, lifts the inlet needle and allows fuel to flow into the
metering chamber.
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Carburetor Basics
Start up
A rich fuel-to-air mixture is required at startup because of the lower
cranking speed (compared to running) which causes less air flow, and
the fact that the engine is usually cold. (A cold engine is not efficient at
vaporizing fuel because heat is required to vaporize liquid.)
The above two conditions can be overcome by closing the choke (a)
and opening the throttle (b) slightly. This creates a high vacuum within
the carburetor’s throat which causes all fuel nozzles to deliver fuel into
the intake air stream.
a
b
wc_gr005109
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Carburetor Basics
WM 80 Repair
Idle
Once the engine starts, the choke (a) is opened and the throttle (b)
nearly closed. The engine is at the idle state. During idle, low pressure
exists on the engine side of the throttle and atmosphere pressure
(high) on the other. Atmosphere air enters the fuel nozzles (transition
holes) and mixes with the fuel in the idle pocket (c). Fuel is drawn out
of the idle pocket on the engine side of the throttle and into the engine.
Atmosphere pressure presses on the metering diaphragm which
opens the needle valve to keep a supply of fuel in the lower chamber.
A check valve (d) in the main nozzle prevents atmosphere air from
entering the fuel passages.
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Carburetor Basics
Partial Throttle Operation
At partial throttle, the choke (a) remains in the open position and the
throttle (b) is partially opened. During partial throttle, low pressure
exists on the engine side of the throttle plate. The low pressure draws
fuel from the three progression fuel nozzles (d). As low pressure
begins to fill the carburetor throat, the check valve starts to open and
fuel begins to flow from the main nozzle (e).
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Carburetor Basics
WM 80 Repair
Wide-Open Throttle Operation
At wide-open throttle, the choke (a) remains in the open position and
the throttle (b) is wide open. During this state, the throttle plate has little
affect on high- and low-pressure areas within the carburetor throat.
The venturi of the carburetor throat now takes over to create the lowpressure area. The low pressure created by the venturi draws fuel into
the air stream. It also acts on the metering diaphragm which opens the
needle valve to its furthest-open position, allowing supply fuel into the
lower chamber. Fuel now flows from the main nozzle (e) located within
the venturi. Very little fuel flows from the idle nozzles.
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Carburetor Basics
Air Purge System
The Walbro carburetor has an air purge system. The air purge system
removes air from the fuel passages so that only fuel fills the carburetor
and the fuel lines.
The heart of the air purge system is the bulb. The bulb works in
conjunction with a number of check valves. Pressing the bulb forces air
(and fuel) through the discharge port back to the tank. Releasing the
bulb creates a vacuum within the fuel passages and sucks air (and
fuel) into the bulb. The metering diaphragm is also pulled by the
suction. This pulls the inlet needle from its seat and allows air (and fuel)
to move from the pumping chamber into the metering chamber. This
air (and fuel) is then expelled by pressing the bulb. Pressing the bulb
until it is filled with only fuel, the purging process is complete.
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Carburetor Basics
5.3
WM 80 Repair
Versions of Tillotson Carburetor
See Graphic: wc_gr002889
1) Dual Needle
Dual needle carburetors have mixture needle valves that are
adjustable. One of the valves (a) adjusts the high-speed jet (H) and the
other valve (b) adjusts the low-speed jet (L). The needle valves operate
by increasing or decreasing the size of the fuel passage to the
discharge ports.
2) Single Needle
Single needle carburetors use a fixed, high-speed fuel jet. No
adjustment of this jet can be made. A low-speed-mixture needle valve
(c) is used to adjust the low-speed jet (L) which controls the idle mixture
and the idle speed. The needle valve operates by increasing or
decreasing the size of the fuel passage to the discharge ports.
3) Fixed-jet, Primary-idle-bypass
Fixed-jet, primary-idle-bypass versions use fixed high-speed and fixed
low-speed jets. No adjustment of either jet can be made. A separate
bypass circuit provides the air/fuel mix to run the engine at idle.
a
1
H
b
2
c
L
3
wc_gr002889
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5.4
Carburetor Basics
Tillotson Carburetor Operation
See Graphic: wc_gr002891
Fuel Pump:
The Tillotson carburetor uses a flexible diaphragm fuel pump (a) to
operate an inlet valve (b) which controls fuel flow to the carburetor fuel
reservoir (c). The fuel pump operates by reacting to pressure changes
in the engine crankcase transmitted through an impulse line (d). The
impulse line can be external (connected to the crankcase through a
plastic tube), or internal to the carburetor (connected through an orifice
drilled in the carburetor adapter) depending on carburetor version.
During the compression stroke, the vacuum created in the crankcase
is transmitted to the carburetor through the impulse line. The vacuum
pulls the fuel pump diaphragm upward. The upward movement of the
diaphragm creates a vacuum in the fuel reservoir which opens the fuel
inlet valve and draws fuel into the fuel reservoir. During the engine’s
power stroke, positive crankcase pressure, also transmitted through
the impulse line, pushes the diaphragm down. The downward
movement of the diaphragm closes the inlet valve and forces fuel
toward the inlet needle valve (e).
c
a
d
b
e
wc_gr002891
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Carburetor Basics
WM 80 Repair
See Graphic: wc_gr002892
Inlet Needle Valve:
The inlet needle valve (e) controls fuel flow into the fuel chamber. This
valve is operated by a second diaphragm called the control diaphragm
(f). The control diaphragm is activated by the vacuum created when air
moves past the venturi (g) of the carburetor throat. A vent (h) to the
atmosphere provides the air pressure differential needed to create the
vacuum. The vent can be direct to outside the carburetor or it may be
upstream of the discharge ports through an orifice drilled in the
carburetor body. The vacuum draws the control diaphragm towards
the carburetor throat and in turn opens the inlet needle valve allowing
fuel into the fuel chamber (i). Suction at the engine intake draws fuel
out of the fuel chamber through the discharge ports (j) into the
carburetor throat. As the fuel in the chamber is used up, atmospheric
pressure pushes in on the opposite side of the diaphragm pushing it
towards the throat of the carburetor. This diaphragm action lowers the
inlet needle valve and allows fuel to fill the fuel chamber. The fuel
pushes the diaphragm away from the carburetor throat and in turn
closes the inlet needle valve. In actual practice, the inlet needle valve
assumes an averaging position where the amount of fuel entering
exactly replaces the amount being used.
g
j
e
i
h
f
wc_gr002892
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Carburetor Basics
See Graphic: wc_gr002893
Start-up mode (choke):
During cold start-up, the choke shutter (butterfly) (k) is closed and the
throttle shutter (l) is partially open. As the engine is turned over, engine
suction draws fuel from the primary (m), secondary (n), and main fuel
(o) discharge ports. Since the choke is closed, the amount of air
flowing through the carburetor is very restricted. As a result, a rich fuel
mixture (fuel mixed with a relatively small amount of air) is delivered to
the engine which allows the engine to start more readily than a lean
mixture.
k
l
n
o
m
wc_gr002893
See Graphic: wc_gr002894
Idle Speed:
At idle speed, only a small amount of air flow through the carburetor is
required. The air flow is regulated by the throttle shutter alone because
the choke is open. However, the throttle shutter regulates the air flow
differently, depending on the version of the carburetor used.
In dual-needle versions (1), the throttle shutter (p) is adjusted by an idle
speed screw. The idle speed is also regulated by the slow speed
mixture needle valve (s). By turning the valve, the fuel/air mixture can
be made richer or leaner, affecting the engine’s speed (rpm).
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WM 80 Repair
In single-needle versions (2), the throttle shutter does not open and
there is no idle speed screw; instead, a small hole (q) in the shutter
regulates the air flow. The idle speed is also regulated by the slow
speed mixture needle valve (t). By turning the valve, the fuel/air mixture
can be made richer or leaner, affecting the engine’s speed (rpm).
In fixed-jet, primary-idle-bypass versions (3), a separate port (r) leads
from the fuel chamber through the carburetor adapter, through a short
hose, then directly into the engine crankcase. The fuel/air mix traveling
through this line keeps the engine running at idle. An idle speed screw
is then used to adjust the throttle shutter and fine-tune the engine
speed.
1
p
s
q
t
2
3
r
wc_gr002894
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Carburetor Basics
See Graphic: wc_gr002895
Partial Throttle:
At partial throttle, the throttle shutter is partially opened, allowing a
greater amount of air through the carburetor. The throttle has opened
wide enough to expose the secondary idle discharge port (a) which
provides more fuel to mix with the air.
In dual-needle versions, engine suction draws fuel from both the
primary (b) and secondary idle discharge ports. As at idle, the slow
speed mixture needle valve regulates the engine speed. By turning the
valve, the fuel/air mixture can be made richer or leaner, affecting the
engine’s speed (rpm).
In single-needle versions, engine suction also draws fuel from both the
primary (b) and secondary idle discharge ports. And like dual needle
carburetors, the adjustable mixture needle valve regulates the engine
speed. By turning the valve, the fuel/air mixture can be made richer or
leaner, affecting the engine’s speed (rpm).
In fixed-jet, primary-idle-bypass versions, only the secondary
discharge port provides fuel at partial throttle. Both high- and lowspeed jets are fixed; no adjustments to jets can be made.
a
b
wc_gr002895
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WM 80 Repair
See Graphic: wc_gr002896
Full Throttle:
The wider the throttle shutter opens, the more air that will flow through
the carburetor. As the air reaches the venturi (c), it is forced to flow
faster to keep the same volume of air flowing. The faster the air flows
through the venturi, the lower the air pressure in the venturi becomes.
When the air pressure becomes lower than the pressure (atmospheric)
on the fuel in the fuel chamber (d), fuel will flow out through the main
discharge port (e) into the throat of the carburetor. The fuel mixes with
the air stream, flows through the carburetor adapter, and into the
engine crankcase.
In summary, the wider the throttle is open, the faster the air will flow.
The faster the air flows, the lower the air pressure. The lower the air
pressure, the more fuel that will flow out. The more fuel that flows out,
the faster the engine runs. This phenomenon is true at any speed and
allows the carburetor to maintain the same approximate fuel-to-air ratio
as the throttle shutter (flow of air) varies.
The fuel will also flow out of the secondary discharge port and, in dualand single-needle versions, out of the primary idle port as well.
c
e
d
wc_gr002896
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5.5
Carburetor Basics
Bing Carburetor Operation
g
e
f
b
c
h
d
a
wc_gr002897
See Graphic: wc_gr002897
Fuel Feed:
The Bing carburetor does not use a fuel pump; instead, the fuel supply
is gravity fed. A priming button (a) is used during the initial start-up to
manually open the inlet needle valve (b) which primes the fuel chamber
(c).
Inlet Needle Valve:
While the engine is running, fuel flow into the fuel chamber is controlled
by the inlet needle valve. The inlet needle valve is operated by the
control diaphragm (d). The control diaphragm is activated by the
vacuum created when air moves through the carburetor throat. A vent
to atmosphere provides the air pressure differential needed to create
the vacuum. This vacuum draws the control diaphragm towards the
carburetor throat and in turn opens the inlet needle valve allowing fuel
into the fuel chamber. Suction at the engine intake draws fuel out of the
fuel chamber, through the discharge ports into the carburetor throat.
As the fuel in the chamber is used up, atmospheric pressure pushes in
on the opposite side of the diaphragm pushing it towards the throat of
the carburetor. This diaphragm action lowers the inlet needle valve and
allows fuel to fill the fuel chamber. This fuel pushes the diaphragm
away from the carburetor throat and in turn closes the inlet needle
valve. In actual practice, the inlet needle valve assumes an averaging
position whereby the amount of the fuel entering exactly replaces the
amount being used.
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Partial Throttle:
At partial throttle, the throttle shutter is partially opened allowing a
greater amount of air through the carburetor. The throttle has opened
wide enough to expose the secondary-idle discharge port and the
engine suction draws fuel from both the primary-idle and secondaryidle discharge ports.
Idle and Low Speed:
The amount of air flowing through the carburetor is regulated by the
throttle and choke shutters. At idle, only a small amount air flow is
needed. This air flow is regulated by the throttle shutter alone, because
the choke is open and no longer affects air flow. Idle speed can be
adjusted by the idle speed screw (e).
Start-up Mode (Choke):
During cold start-up, the choke shutter (butterfly) is closed and the
throttle shutter is partially open. As the engine is turned over, engine
suction draws fuel from the primary, secondary, and main fuel
discharge ports. Because the choke is closed, the amount of air
flowing through the carburetor is very restricted. As a result, a rich fuel
mixture (fuel mixed with a relatively small amount of air) is delivered to
the engine which allows the engine to start more easily.
Full Throttle:
As the throttle continues to open, the velocity of the air through the
carburetor venturi (f) increases and creates a low pressure area over
the main fuel discharge port (g). When the air pressure in the venturi
becomes lower than the pressure on the fuel in the fuel chamber (h),
the fuel will flow out into the throat of the carburetor and mix with the
air stream. The fuel will also flow out of the primary and secondary
discharge ports. The wider the throttle is opened, the more air that will
flow through the carburetor. The more air flowing, the faster it will flow
over the venturi. The faster over the venturi, the lower the pressure
over the main discharge port and thus the more fuel which will flow out
into the air stream. This phenomenon allows the carburetor to maintain
the same approximate air/fuel ratio as the air flow varies.
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Carburetor Basics
Notes
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Carburetor Basics
5.6
WM 80 Repair
Carburetor Adapters
See Graphic: wc_gr007414
The function of the carburetor adapter is to control the amount of fuel/
air mixture that can reach the engine. When used in combination with
the carburetor fuel jets, the power and speed of the engine is
controlled. This allows the WM 80 engine to adapt to the power and
speed requirements of different machine models.
No matter the style, all adapters control the fuel/air mixture through
bore diameter (d) size. Each application calls for a specific adapter and
it is important that the correct adapter be used. Consult the parts book
for the proper one.
NOTICE: Using the wrong adapter may cause the engine to overspeed
or lose power, resulting in excessive engine wear and reduced
performance.
1. This plastic, elbow-style adapter is used with Tillotson carburetors
that have fixed mixture needle valves with primary-idle-bypass circuit.
This adapter is used on rammers.
2. This plastic, elbow-style adapter is used with Tillotson carburetors
that have single- or dual-mixture needle valves. This adapter is used
on rammers.
3. This straight-through-style adapter is used with both Bing and
Tillotson carburetors that have single- or dual-mixture needle valves. It
has an insulating layer (e) that helps retard heat transfer. This adapter
is used on rammers, breakers, and vibroplates.
4. This plastic, straight-through-style adapter was used with both Bing
and Tillotson carburetors. The carburetor mounts to a metal band (f)
embedded in the shaft of the adapter. This adapter was used on
rammers, breakers, and vibroplates.
5. This metal, straight-through-style adapter was used with both Bing
and Tillotson carburetors. An insulating spacer (g) and gaskets (h) are
used in assembling this adapter to the engine. This adapter was used
on rammers, breakers, and vibroplates.
6. This composite, straight-through-style adapter is used exclusively
with Tillotson carburetors. It can be found on rammers.
7. This composite, straight-through-style adapter is used exclusively
with Walbro carburetors. It can be found on rammers.
8. This elbow-style adapter is used with Walbro carburetors that utilize
the auto-release choke. This adapter is used on rammers.
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Carburetor Basics
d
1
d
2
d
d
3
f
4
e
d
5
h
g
6
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65
Carburetor Replacement
6
6.1
WM 80 Repair
Carburetor Replacement
Replacing the Walbro Carburetor (auto-release choke models)
Removal
6.1.1
Stop the machine and allow it to cool.
6.1.2
Remove the carburetor guard (a).
6.1.3
Loosen the hose clamp and remove the air duct (b).
6.1.4
Disconnect the ignition wire (c) from the spark plug.
6.1.5
Loosen the clamp (d) and remove the throttle cable (e) from the
carburetor adapter (f).
6.1.6
Remove the two nuts and washers and remove the carburetor
assembly (g) from the machine.
This procedure continues on the next page.
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Carburetor Replacement
Continued from the previous page.
6.1.7
Have a container ready, then remove the oil hose (h) and drain it.
6.1.8
Make sure the throttle is in the OFF position. This position also closes
the fuel valve. Then, remove the fuel hose (n) and drain it.
6.1.9
Remove the gasket (m).
6.1.10 Disassemble the carburetor (i) from the adapter (j), flange (k), and
gaskets (l and o).
Result
The removal procedure is now complete.
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WM 80 Repair
Installation
Perform the procedure below to install the carburetor
6.1.1
Assemble the adapter (j), lower gasket (l), flange (k), and upper
gasket (o) to the carburetor (i). Note: The gaskets are not
interchangeable.
6.1.2
Connect the oil hose (h), and the fuel hose (n), to the carburetor.
6.1.3
Install the carburetor assembly to the engine.
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6.1.4
Carburetor Replacement
Slide the throttle cable (e) through the adapter (f) and reconnect it to
the clamp (d).
d
wc_gr007456
6.1.5
Install the air duct (b) with the hose clamp.
6.1.6
Using Loctite® 243 on the screws, install the carburetor guard (a).
Result
The installation procedure is now complete.
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Carburetor Replacement
6.2
WM 80 Repair
Removing Walbro Carburetor (standard choke models)
6.2.1
Stop the machine and allow it to cool.
6.2.2
Place the throttle in the OFF position.
6.2.3
Disconnect the ignition wire (a) from the spark plug.
6.2.4
Remove the carburetor guard (b).
6.2.5
Loosen the hose clamp (c) and remove the air duct (d).
6.2.6
Remove the two screws and remove the flange (e) and the carburetor
from the machine.
6.2.7
Remove the screws (f) and remove the adapter (g).
6.2.8
Disconnect the throttle cable (h). Remove the spring (i).
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Carburetor Replacement
Notes
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71
Carburetor Replacement
6.3
WM 80 Repair
Removal, Tillotson with composite adapter
See Graphic: wc_gr002929
6.3.1
Stop the machine and allow it to cool.
6.3.2
Close the fuel valve (a) (if equipped).
6.3.3
Disconnect the ignition wire (b) at the spark plug.
6.3.4
Remove the carburetor guard (c).
6.3.5
Loosen the clamps holding the air duct (d) to the carburetor and
remove the air duct from the carburetor.
6.3.6
Remove the two socket head cap screws (e) holding the flange (f) to
the carburetor (g) and remove both the flange and the carburetor.
6.3.7
Disconnect and plug the fuel line(s) (h) to the carburetor.
6.3.8
To remove the carburetor adapter (i), loosen the two screws (j) and the
nut (k) holding the throttle cable (l). Then, remove the two nuts (m) and
remove the carburetor adapter.
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Carburetor Replacement
m
i
g
f
e
d
b
a
d
c
e
l
h
j
m
i
f
g
k
wc_gr002929
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Carburetor Replacement
6.4
WM 80 Repair
Tillotson with Straight-Through Adapters
See Graphic: wc_gr002898
6.4.1
Turn off the fuel valve at the tank and disconnect the spark plug lead
wire.
6.4.2
Remove the air filter pipe (loosen both clamps).
6.4.3
Disconnect the throttle cable.
6.4.4
Loosen the clamp which secures the carburetor to the adapter and
slide the carburetor off.
6.4.5
Protect the cylinder from dirt by cranking the engine until the piston is
covering the intake port.
wc_gr002898
6.5
Tillotson with Elbow Adapters
See Graphic: wc_gr002899
6.5.1
Turn off the fuel valve at the tank and disconnect the spark plug lead
wire.
6.5.2
Loosen the air filter pipe clamp and remove the carburetor adapter
nuts. Remove the assembly from the engine.
6.5.3
Disconnect the throttle cable.
6.5.4
Remove the air duct from the carburetor and the carburetor from the
adapter.
6.5.5
Protect the cylinder from dirt by cranking the engine until the piston is
covering the intake port.
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wc_gr002899
6.6
wc_gr002900
Bing
See Graphic: wc_gr002900
wc_tx000522gb.fm
6.6.1
Turn off the fuel valve at the tank and disconnect the spark plug lead
wire.
6.6.2
Remove the air filter pipe (loosen both clamps).
6.6.3
Disconnect the throttle cable.
6.6.4
Loosen the clamp which secures the carburetor to the adapter and
slide the carburetor off the adapter.
6.6.5
Protect the cylinder from dirt by cranking the engine until the piston is
covering the intake port.
75
Carburetor Overhaul
7
WM 80 Repair
Carburetor Overhaul
7.1
Walbro Carburetor Exploded View (auto-release choke models)
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7.2
Ref
Carburetor Overhaul
Walbro Carburetor Components (auto-release choke models)
Description
Ref
Description
1
Screw
21
Screw
2
Cover
22
Screw
3
Gasket
23
Cover
4
Diaphragm
24
Bulb
5
Screen
25
Valve
6
Washer
26
Air purge body assembly
7
Spring
27
Diaphragm
8
Choke shaft
28
Gasket
9
Spacer
29
Nozzle
10
Throttle lever
30
Spring
11
Screw
31
Needle
12
Swivel
32
Needle valve
13
Retaining ring
33
Idle speed screw
14
Inlet valve
34
Spring
15
Lever
35
Throttle shaft
16
Pin
36
Choke lever
17
Screw
37
Sleeve
18
Spring
38
Screw
19
Plug
39
Choke valve
20
Throttle valve
—
—
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Carburetor Overhaul
7.3
WM 80 Repair
Rebuilding the Walbro Carburetor (auto-release choke models)
Disassembly
7.3.1
Remove the cover (a) from the fuel-pump side of the carburetor.
7.3.2
Remove the fuel pump diaphragm and gasket (b).
7.3.3
Remove the bracket and the air purge bulb (c). Separate the bulb
from the bracket.
7.3.4
Remove the air purge body assembly (d). Remove the combination
valve (e).
7.3.5
Remove the metering diaphragm (f).
wc_gr007436
7.3.6
Remove the screw (j), metering lever (h), pin (k), spring (g), and inlet
needle (i).
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Carburetor Overhaul
7.3.7
Remove the shutter (l) (butterfly).
7.3.8
Remove the screw (m), lever (n), washer (o), and spacer (p).
7.3.9
Remove the retaining ring (q), then remove the choke shaft (r).
7.3.10 Remove the shutter (t) (butterfly) from the throttle shaft.
7.3.11
Remove the throttle lever (u), spacer (v), and washer (w).
7.3.12 Remove the throttle shaft (aa) and the spring (bb).
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7.3.13 Non-EPA regulated countries only. Remove the high- and low-speed
needle valves (x and y).
x
y
wc_gr005125
7.3.14 Using a punch, remove the Welch plug (z).
7.3.15
Non-EPA regulated countries only. Press out the main nozzle (zz).
7.3.16 Remove the screen(s) (dd).
Result
The disassembly procedure is now complete.
80
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Carburetor Overhaul
Reassembly
7.3.1
Align the hole in the main nozzle (zz) with the passage of the highspeed needle. Press the main nozzle into the carburetor body until the
top of the main nozzle is flush with the carburetor body.
7.3.2
Install the Welch plug (z). Tap it in with a flat punch.
7.3.3
Install the high- and low-speed needles (x and y). Note: The high-speed
needle is shorter than the low-speed needle.
7.3.4
Install the screen(s) (dd).
7.3.5
Install the spring (bb) to the throttle shaft (aa). Install the washer (cc),
then slide the throttle shaft into the carburetor body.
7.3.6
Install the washer (w), spacer (v), and the throttle lever (u).
This procedure continues on the next page.
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Carburetor Overhaul
WM 80 Repair
Continued from the previous page.
7.3.7
Install the shutter (t) (butterfly).
7.3.8
Install the spring and washer on the choke shaft, then install the
choke shaft (r) into the carburetor body.
7.3.9
Align the spring (ee) as shown, then secure the choke shaft with
retaining ring (q).
7.3.10 Install the spacer (p), washer (o), lever (n), with screw (m).
7.3.11
Install the shutter (l) (butterfly).
This procedure continues on the next page.
82
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Carburetor Overhaul
Continued from the previous page.
7.3.12 Install the screw (j), metering lever (h), pin (k), spring (g), and inlet
needle (i).
7.3.13 Install the metering diaphragm (f).
7.3.14 Install the combination valve (e) into the air purge body assembly (d),
then install the air purge body assembly.
7.3.15 Install the air purge bulb (c) and bracket.
7.3.16 Install the fuel pump diaphragm (b).
7.3.17 Install the cover (a).
Result
The reassembly procedure is now complete.
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83
Carburetor Overhaul
7.4
WM 80 Repair
Walbro Carburetor Exploded View (standard choke models)
wc_gr005118
84
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7.5
Ref
Carburetor Overhaul
Walbro Carburetor Components (standard choke models)
Description
Ref
Description
1
Screw
20
Bulb
2
Cover
21
Combination valve
3
Gasket
22
Air purge body assembly
4
Diaphragm
23
Diaphragm
5
Screen
24
Gasket
6
Washer
25
Nozzle
7
Spacer
26
Idle needle
8
Lever
27
Power needle
9
Screw
28
Spring
10
Inlet needle
29
Screw
11
Metering lever
30
Spring
12
Throttle shutter
31
Throttle shaft
13
Screw
32
Choke shaft
14
Pin
33
Spacer
15
Spring
34
Screw
16
Screw
35
Choke shutter
17
Welch plug
36
Ball
18
Screw
37
Spring
19
Cover
---
---
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Carburetor Overhaul
7.6
WM 80 Repair
Rebuilding the Walbro Carburetor (standard choke models)
Disassembly
7.6.1
Remove the cover (a) from the fuel-pump side.
7.6.2
Remove the fuel pump diaphragm and gasket (b).
7.6.3
Remove the bracket and the air purge bulb (c). Separate the bulb
from the bracket.
7.6.4
Remove the air purge body assembly (d). Remove the combination
valve (e).
7.6.5
Remove the metering diaphragm (f).
7.6.6
Remove the screw (j), metering lever (h), pin (k), spring (g), and inlet
needle (i).
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Carburetor Overhaul
7.6.7
Remove the shutter (l) (butterfly).
7.6.8
Remove the choke shaft (m) and spacer (n). Also remove the ball (o)
and the spring (p) from the carburetor body.
7.6.9
Remove the throttle lever (q), spacer (r), and washer (s).
7.6.10 Remove the shutter (t) (butterfly), then pull the throttle shaft (u) from
the carburetor body. Remove the spring (v) and nipple (w).
7.6.11
Non-EPA regulated countries only. Remove the high- and low-speed
needle valves (x and y).
x
y
wc_gr005125
7.6.12 Using a punch, remove the Welch plug (z).
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87
Carburetor Overhaul
7.6.13
WM 80 Repair
Non-EPA regulated countries only. Press out the main nozzle (zz).
The procedure is now complete.
Reassembly
7.6.1
Align the hole in the main nozzle (zz) with the passage of the highspeed needle. Press the main nozzle into the carburetor body until the
top of the main nozzle is flush with the carburetor body.
7.6.2
Install the Welsh plug (z). Tap it in with a flat punch.
7.6.3
Install the high- and low-speed needles (x and y). Note: The high-speed
needle is shorter than the low-speed needle.
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Carburetor Overhaul
x
y
wc_gr005128
7.6.4
Install the spring (v) to the throttle shaft (u). Install the throttle shaft
into the carburetor body and install the shutter (t) (butterfly).
This procedure continues on the next page.
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89
Carburetor Overhaul
WM 80 Repair
Continued from the previous page.
7.6.5
Install the washer (s), spacer (r), and the throttle lever (q). Note the
positioning of the throttle lever (q) compared to the throttle shaft (u).
u
wc_gr005130
7.6.6
Install the spring (p) and ball (o). Install the spacer (n) and choke shaft
(m).
wc_gr005131
7.6.7
Install the shutter (l) (butterfly).
7.6.8
Install the inlet needle (i), spring (g), pin (k), and metering lever (h)
with the screw (j).
7.6.9
Install the new diaphragm (f) and the new gasket. Be sure the
diaphragm hooks into the metering lever.
This procedure continues on the next page.
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Carburetor Overhaul
Continued from the previous page.
7.6.10 Install the combination valve (e). Install the air purge body assembly
(d), bracket, and air purge bulb (c).
7.6.11
Install the new fuel pump diaphragm then the new gasket (b). Be sure
to align each with the positioning pins.
7.6.12 Install the cover (a).
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91
Carburetor Overhaul
7.7
WM 80 Repair
Tillotson Carburetor Exploded View
44
1
2
3
4
34
7
6
35
5
40
35
33
8
28
28
9
31
32
30
28
29
27
10
38
37
13
26
25
24
12
11
7
23
14
15
43
41
16
42
17
43
41
22
20
21
18
21
19
39
20
20
21
22
wc_gr002901
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7.8
Carburetor Overhaul
Tillotson Components
See Graphic: wc_gr002901
Ref
Description
Ref
Description
1
Screw
23
Control lever
2
Cover
24
Plug
3
Gasket
25
Retaining ring
4
Diaphragm
26
Screen
5
Screen
27
Plug
6
Elbow fitting
28
Bushing
7
Screw w/ lock washer
29
Bushing
8
Clip
30
Choke shaft
9
Spring
31
Throttle shaft
10
Ball
32
O-Ring
11
Choke shutter
33
Spring
12
Needle-fuel inlet
34
Gasket
13
Spring
35
Throttle shutter
14
Pin
37
Screw
15
Screw
38
Spring
16
Gasket
39
Low-speed jet
17
Diaphragm
40
Screw
18
Cover
41
Low-speed screw
19
Screw w/ lock washer
42
High-speed screw
20
Screw
43
Spring
21
Washer
44
Fitting (impulse line)
22
Main jet
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Carburetor Overhaul
7.9
WM 80 Repair
Bing Carburetor Exploded View
45
46
1
44
2
3
43
40
41
42
41
40
39
4
5
6
5
34
7
35
8
36
33
9
10
32
13
38
11
30
31
27
29
28
14
17
26
25
37
12
16
15
18
20
19
24
23
21
21
22
22
wc_gr002902
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Carburetor Overhaul
7.10 Bing Carburetor Components
See Graphic: wc_gr002902
Ref
Description
Ref
Description
1
Retaining ring
24
Gasket
2
Washer
25
Diaphragm
3
Spring
26
Screw
4
Brake control
27
Pin
5
Washer
28
Control lever
6
Throttle control lever
29
Spring
7
Carburetor body
30
Needle
8
Choke
31
Clamp
9
Spring
32
Nut
10
Idle stop screw
33
Screw
11
Choke lever
34
Sealing ring
12
Nut
35
Cover
13
Main jet #62
36
Fuel filter screen
14
Idle jet #35
37
Washer
15
Plug
38
Gasket
16
Plug
39
Spacer
17
Nut
40
Washer
18
Adjustment screw
41
Spacer
19
Clamp screw
42
Retaining ring
20
Bracket
43
Spring
21
Lockwasher
44
Screw
22
Screw
45
Throttle shutter
23
Cover
46
Throttle shaft
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Carburetor Inspection and Adjustment
8
WM 80 Repair
Carburetor Inspection and Adjustment
8.1
Inspection
Diaphragms:
•
Check for tears, punctures, and distortion in the elastic material.
Replace the diaphragm if it appears stretched or puckered.
•
Be certain diaphragms are installed correctly. See appropriate
exploded view. On Walbro and Tillotson carburetors, be sure that
the control diaphragm is connected to the inlet lever.
•
Evenly tighten all screws securing the diaphragm covers to
ensure good seal and avoid leaks.
•
Complete repair kits are available: P/N 0171010—Walbro carburetors; P/N 2005690—Tillotson carburetors; P/N 0065689—Bing
carburetors.
Inlet Needle Valve:
•
•
The inlet needle must seal properly or the engine may flood or
run rich. The elastic tip must be in good condition. Replace the
needle if the tip becomes hard or brittle.
Keep the seating area clean and free from dirt. Clean it using
compressed air.
Control Lever Spring:
•
Be certain that the spring is seated correctly under the inlet lever
and that it has enough tension to seat the inlet needle. Replace
the spring if worn or broken. Do not stretch the spring.
Adjustable Mixture Needle Valves (Tillotson):
•
On Tillotson carburetors with adjustable mixture needle valves,
the valves must have absolutely smooth points. Replace the needle valves if the taper appears worn or damaged.
NOTICE: Do not turn in the adjusting screws too tight or the valve
seats may be damaged.
Fixed Jets:
•
Clean the jet orifice using compressed air. Use a narrow screwdriver when installing jets to avoid shaving metal from inside of
the carburetor body which could plug the jet orifice.
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8.2
Carburetor Inspection and Ad-
Adjusting the Inlet Control Lever
See Graphic: wc_gr002903
Walbro:
Use the special tool (e) to set height of metering lever.
Tillotson:
Set the inlet control lever (a) so that it is flush with the floor of the fuel
chamber (b). Bend the end of the control lever up or down as required.
Bing:
Set the inlet control lever so that it is 1.4 mm (0.055 in.) below the
surface of the carburetor casting by bending the tab up or down as
required. Check the distance with the carburetor gauge (c). If no gauge
is available, set the distance to be 0.8 mm (0.030 in.) between the tip
of the lever and the bottom of the fuel chamber with a feeler gauge (d).
On Bing carburetors using molded plastic lever, no inlet lever
adjustment is required.
e
a
b
1.4 mm (0.050 in.)
c
d
0.8 mm
(0.030 in.)
wc_gr002903
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97
Carburetor Inspection and Adjustment
8.3
WM 80 Repair
Carburetor Adjustments
Walbro:
Procedures apply in only non-EPA regulated applications.
Both high- and low-speed mixture adjustment is possible. A special
tool is required. See section Operating & Idle Speeds for correct
operating and idle speed settings. For best accuracy use a tachometer
when making carburetor adjustments.
For initial carburetor set-up after rebuilding, complete the following
procedures:
8.3.1
Turn in (clockwise) high- (H) and low-speed mixture needle valve (L)
by hand until tight.
NOTICE: Do not overtighten the valves. Damage to the valve seats
may result.
Preset the fuel jets as follows:
8.3.2
Open the low-speed needle valve 1-1/2 revolutions counterclockwise.
8.3.3
Open the high-speed needle valve 3-1/2 revolutions counterclockwise.
8.3.4
Start the engine and allow it to run at high speed for 3–6 minutes.
Check the adjustments by running the machine at full throttle and at
idle several times. Keep the choke fully open. If further adjustments are
necessary, continue with step 5.
Note: After full throttle operation, allow engine to idle one minute
before making any adjustments.
8.3.5
When making carburetor adjustments, turn the valve screws in small
increments, no more than 1/16 of a revolution (turn) at a time. Turn the
screws clockwise to lean, counterclockwise to enrich. Allow 5 seconds
after each adjustment for engine to stabilize.
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Carburetor Inspection and Ad-
See Graphic: wc_gr002904
Tillotson Dual Needle:
Both high- and low-speed mixture adjustment is required on dual
needle models. See section Operating & Idle Speeds for correct
operating and idle speed settings. For best accuracy use a tachometer
when making carburetor adjustments.
For initial carburetor set-up after rebuilding, complete the following
procedures:
8.3.6
Turn in (clockwise) high- (H) and low-speed mixture needle valve (L)
by hand until tight.
NOTICE: Do not overtighten the valves. Damage to the valve seats
may result.
Preset the fuel jets as follows:
8.3.7
Open the low-speed needle valve 3/4 revolution counterclockwise.
8.3.8
Open the high-speed needle valve 1-1/4 revolutions counterclockwise.
8.3.9
Start the engine and allow it to run at high speed for 3–6 minutes.
Check the adjustments by running the machine at full throttle and at
idle several times. Keep the choke fully open. If further adjustments are
necessary, continue with step 5.
Note: After full throttle operation, allow engine to idle one minute
before making any adjustments.
8.3.10
When making carburetor adjustments, turn the valve screws in small
increments, no more than 1/16 of a revolution (turn) at a time. Turn the
screws clockwise to lean, counterclockwise to enrich. Allow 5 seconds
after each adjustment for engine to stabilize.
8.3.11
Check the low-speed adjustment first by accelerating the machine to
high speed. If the engine bogs down during acceleration and/or dies,
the carburetor is set too lean. If the engine bogs down then accelerates
slowly, the carburetor is set too rich. Adjust low speed until good
acceleration is achieved. Re-adjust idle speed screw for required idle
speed.
8.3.12
Adjust the high speed screw to obtain the best operating speed.
Running too lean or too rich will cause the engine to run at a lower rpm
than optimal. If the high-speed needle valve is set too rich, the engine
will emit black smoke from the muffler.
NOTICE: Because the engine is lubricated by the fuel mixture, do not
lean-out the carburetor too much; the engine may overheat and
damage components.
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Carburetor Inspection and Adjustment
WM 80 Repair
H
L
L
wc_gr002905
wc_gr002904
See Graphic: wc_gr002905
Tillotson Single Needle:
On single-needle Tillotson carburetors the high-speed fuel jet is fixed;
only the low-speed jet can be adjusted. See section Operating & Idle
Speeds for correct operating and idle speed settings. For initial
carburetor set-up after rebuilding, complete the following procedures:
8.3.13 Turn in (clockwise) the low-speed mixture valve (L) by hand until tight.
NOTICE: Do not overtighten valve. Damage to valve seats may result.
8.3.14 Preset the low-speed mixture valve by opening it 1 revolution (turn)
counterclockwise.
8.3.15 Start the engine and allow it to warm up to operating temperature by
running it at high speed for 3–6 minutes.
8.3.16 Set the engine idle speed with the engine throttle control closed and
the choke fully open. Adjust the low-speed mixture valve until the
correct low speed is set. Turn the valve clockwise to lean,
counterclockwise to enrich.
Tillotson Idle By-pass and Bing Carburetors:
These carburetors use fixed jets for high- and low-speed operation,
and no adjustments are required. Correct idle speed is obtained by
adjusting the idle speed screw. Adjust idle speed with the throttle
control closed, the choke open, and the machine warm. See section
Operating & Idle Speeds for correct operating and idle speed settings.
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9
Carburetor Troubleshooting
Carburetor Troubleshooting
9.1
Troubleshooting Walbro Carburetors
Problem
Probable Cause
Remedy
Engine floods.
Worn inlet needle body or tip.
Replace the inlet needle.
Inlet needle sticking
Check spring tension and
metering lever.
Dirt or gum formations preventing the inlet needle from sealing
Remove and clean the carburetor.
Metering lever set incorrectly.
Adjust metering lever.
Diaphragm installed incorrectly
Correct diaphragm installation.
Metering lever set too low.
Adjust metering lever.
Metering lever binding.
Clean metering lever.
Loose mounting bolts.
Tighten mounting bolts.
Main nozzle plugged
Replace the main nozzle.
Fuel hose plugged
Replace the fuel hose.
Idle speed incorrectly adjusted
Reset the idle speed.
Engine will not
accelerate.
Engine will not
idle.
Engine runs rich.
wc_tx000522gb.fm
Throttle not fully returning to idle Adjust throttle cable and inspect
the throttle shaft for sticking.
Throttle plate cocked in the bore
causing fast idle
Reposition throttle plate.
Idle discharge ports plugged
Clean the carburetor or blow it
out with compressed air.
Defective manifold gaskets.
Replace gaskets.
Inlet needle not seating
Clean and/or replace the inlet
needle.
Defective pump diaphragm.
Replace pump diaphragm.
Metering lever set too high.
Adjust metering lever.
Metering lever stuck.
Clean carburetor.
Worn inlet needle body or tip.
Replace the inlet needle.
101
Carburetor Troubleshooting
9.2
WM 80 Repair
Troubleshooting Tillotson and Bing Carburetors
Problem
Probable Cause
Remedy
Engine floods.
Defective or missing fuel filter
allowing dirt to enter carburetor
Install a new fuel filter.
Inlet needle sticking
Check spring tension and axle
point.
Dirt or gum formations preventing the inlet needle from sealing
Remove and clean the carburetor.
Inlet control lever set
Adjust inlet control lever.
Control lever spring not seated
on lever
Remove and either replace or
reinstall the control lever.
Diaphragm installed incorrectly
Correct diaphragm installation.
Idle mixture is too lean.
Adjust idle mixture.
Diaphragm cover plate loose;
air leak
Check and tighten the cover
plate.
Inlet control lever is set incorrectly.
Correct the lever adjustment.
Main fuel discharge nozzle
plugged
Clean the carburetor or blow it
out with compressed air.
Control diaphragm punctured
Replace the diaphragm.
Idle speed incorrectly adjusted
Reset the idle speed.
Engine will not
accelerate.
Engine will not
idle.
Throttle not fully returning to idle Adjust throttle cable and inspect
the throttle shaft for sticking.
Throttle plate cocked in the bore
causing fast idle
Reposition throttle plate.
Idle discharge ports plugged
Clean the carburetor or blow it
out with compressed air.
Inlet control lever incorrectly set
Readjust the inlet control lever.
Inlet needle not seating
Clean and/or replace the inlet
needle.
102
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WM 80 Repair
Engine runs rich.
wc_tx000522gb.fm
Carburetor Troubleshooting
High-speed adjustment incorrect
Readjust the high speed.
High-speed mixture needle
valve damaged
Replace the high-speed mixture
needle valve.
The size of the fixed jet is incorrect.
Replace the fixed jet with correct size.
Plug covering main discharge
port is leaking.
Install new plug.
103
Disassembly and Assembly
WM 80 Repair
10 Disassembly and Assembly
10.1 Tools
Because all possible problems encountered while repairing the
machine cannot be anticipated, it is up to the mechanic to use common
sense and good judgement in tool selection.
The use of any special tools is recommended only for those operations
where the use of conventional tools proves inadequate.
Before substituting another tool or procedure, you should be satisfied
that neither personal injury nor damage to the component will result.
10.2 Special Tools
The following list of special tools will be needed when disassembling
and assembling the machine.
Tool
Part Number
Tool
Part Number
Bearing extractor
0013288
Flywheel puller
0046503
Holding ring
0013290
Pusher tube
(Seal and bearing
installer)
0048585
Split shell puller
0017328
4-shoe clutch puller
(BHF 30S, BS 45Y,
BS 50Y, BS 52Y,
BS 60Y)
0049776
Crankshaft support tube
0023339
2-shoe clutch puller
0117972
Ring compressor
0031986
Clutch puller (BS 62Y,
BS 65Y)
0045064
Crankshaft support plate
0032028
Vacuum test kit
0155268
Split ring puller
0023338
Pressure tester gauge
0079264
104
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WM 80 Repair
Disassembly and Assembly
10.3 Ordering Parts
The repair procedures contained in this manual do not include part
numbers. For parts replacement information, refer to the Parts Book
originally supplied with the machine.
If the original Parts Book has been lost, a replacement may be ordered
from Wacker Neuson Corporation. When ordering a replacement Parts
Book, please list the model number, item number, revision level, and
serial number of the machine. Parts Books are also available on the
Wacker Neuson Corporation Web site. See www.wackerneuson.com.
Enter the site as a visitor.
10.4 Reference Numbers ( )
Repair procedures contain reference numbers enclosed in
parentheses ( ). These numbers refer to the item numbers shown on
the assembly drawings and other detailed drawings. They are included
to aid the mechanic in identifying parts and assembling components.
10.5 Threadlocking Compounds
Due to the heavy vibration inherent in this type of equipment, the repair
and service procedures described in this manual specify the use of
threadlocking compounds. These compounds should be used where
indicated to prevent the fasteners from becoming loose.
Although Loctite® is referred to throughout this manual, any equivalent
type of sealant such as Hernon, Prolock, or Omnifit may be used.
Clean the screw threads and wipe off any oil or grease before applying
a threadlocking compound.
For a complete list of recommended sealing and locking compounds,
refer to the Use of Threadlockers and Sealants chart at the end of this
Repair Manual.
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105
Disassembly and Assembly
WM 80 Repair
10.6 Removing the WM 80 Engine from BS Rammers (auto-release
choke models)
Requirements
•
Engine cool
•
Carburetor removed
Removal
Perform the procedure below to remove the engine.
10.6.1
Remove the carburetor. See topic Removing the Carburetor.
10.6.2 Remove the muffler (a).
10.6.3 Remove the bracket (b).
10.6.4 Disconnect the wiring to the switches (c).
10.6.5 Remove the screws that hold the engine and remove the engine (d)
from the machine.
Result
The engine has now been removed.
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Disassembly and Assembly
Installation
Perform the procedure below to install the engine.
10.6.6
Install the engine (d) to the machine with three screws. Torque the
screws to 28 Nm (20 ft.lbs.).
10.6.7 Reconnect the wiring (c) to the switches.
10.6.8 Install the bracket (b).
10.6.9 Install the muffler (a). Torque screws (x) to 18 Nm (13 ft.lbs.). Torque
screw (y) to 23 Nm (16 ft.lbs.).
10.6.10 Install the carburetor.
Result
The engine has now been installed.
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Disassembly and Assembly
WM 80 Repair
10.7 Removing Engine From BS Model Rammers
(standard choke models)
See Graphic:wc_gr002935
Removal:
10.7.1 Stop the machine and allow it to cool.
10.7.2 Remove the carburetor. See section Removing Carburetor.
10.7.3 Remove the muffler guard (a) (if equipped) and the muffler (b).
10.7.4 Disconnect the connector (c) from the stop switch.
10.7.5 Remove the three socket head cap screws (d) that hold the engine to
the crankcase.
10.7.6 Tilt the engine down and away to remove it from the crankcase.
WARNING
NOTICE: The rammer tips easily when the engine is removed.
DO NOT run the engine while it is off the machine unless the clutch (e)
has been removed. Running the engine with the clutch attached to the
crankshaft will cause the clutch shoes to separate and fly off.
Installation:
10.7.7 Position the engine onto the machine. Using Loctite 234 or equivalent
on the three screws (d), secure the engine to the machine. Torque the
screws to 27 Nm (20 ft.lbs.).
10.7.8 Reconnect the stop switch.
10.7.9 Install the muffler (b) and muffler guard (a).
10.7.10 Install the carburetor. See section Removing Carburetor.
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b
e
a
c
d
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10.8 Removing Engine From BH 23 Breakers
See Graphic: wc_gr002937
Removal:
10.8.1 Stop the machine and allow it to cool.
10.8.2 Remove the screws (a) and lock washers which secure the two shells
together.
10.8.3 Remove the shell (b) opposite the throttle.
10.8.4 Remove the cover of the air cleaner, the air filter (c), and the base of
the air cleaner (d).
10.8.5 Remove the carburetor (e).
10.8.6 Remove the three socket head cap screws (f) that hold the engine to
the crankcase and remove the engine.
Installation:
10.8.7 Position the engine onto the machine and secure it with three socket
head cap screws (f).
10.8.8 Install the carburetor (e).
10.8.9 Install the base of the air cleaner (d), the air filter (c), and the cover of
the air cleaner.
10.8.10 Secure the two shells to the machine with screws (a) and lock
washers.
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b
d
e
c
f
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10.9 Removing Clutch
See Graphic: wc_gr002941
This procedure requires special tool P/N 0117972, puller.
WARNING
DO NOT run the engine while it is off the machine unless the clutch has
been removed. Running the engine with the clutch attached to the
crankshaft will cause the clutch shoes to separate and fly off.
Removal:
10.9.1 Stop the machine and allow it to cool.
10.9.2 Remove the engine from the machine. See section Removing Engine.
10.9.3 Check the condition of the clutch shoes (a) and replace them if
necessary. The clutch shoes should be absolutely dry. If oil is present,
inspect the engine shaft seal.
10.9.4 Prevent the clutch from turning and use an air impact wrench and 17
mm socket to loosen the clutch nut (b). If an impact wrench is not
available, rap the wrench handle sharply to help break the nut loose.
Note: Loosen the nut but do not completely remove it from the engine
crankshaft. This will protect the crankshaft threads from the clutch
puller screw.
10.9.5 Screw the clutch puller (P/N 0117972) (c) (or other suitable puller) into
the small holes in the clutch and turn the center screw against the end
of the crankshaft until the clutch hub breaks free of the taper.
Note: When reinstalling the clutch, make sure the taper in the clutch
hub and on the engine crankshaft is absolutely free of any oil or
grease.
Installation:
10.9.6 Place the clutch on the engine crankshaft.
10.9.7 Reinstall the clutch nut and torque to 35 Nm (25 ft.lbs.).
10.9.8 Reinstall the engine on the crankcase. Torque the screws to 27 Nm (20
ft.lbs.).
10.9.9 Perform an operation check. Clutch should be disengaged with the
throttle at the idle position.
Engine Speed (idle) (rpm): 1500 ± 200
Clutch Engagement (rpm): 2800 ± 200
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b
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10.10 WM 80 Exploded View
11
9
10
12
2
3
1
8
28
4
5
29
26
7
6
27
7
30
31
40
15
25
33
32
24
34
35
23
21
36
22
41
19
17
13
39
20
37 38
14
19
15
18
17
16
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10.11 WM 80 Components
See Graphic: wc_gr002906
Ref
Description
Ref
Description
1
Set-cylinder
21
Needle bearing
2
Stud M6x18
22
Screw M5x55
3
Stud M5x20
23
Ignition module
4
Piston
24
Sleeve
5
Piston ring
25
Screw M5x20
6
Wrist pin
26
Nut M12x1.5
7
Retaining ring
27
Washer
8
Gasket
28
Screw M5x20
9
Screw M6x60
29
Flywheel housing
10
Spark plug
30
Flywheel
11
Spark plug cap
31
Locknut M3
12
Ignition cable
32
Cap
13
Sealing ring
33
Cable guide
14
Screw M5x8
34
Terminal post
15
Shaft seal
35
Screw M3x20
16
Nut M5
36
Woodruff key
17
Crankcase
37
Screw M6x12
18
Gasket
38
Lock washer
19
Ball bearing
39
Starter complete
20
Crankshaft
40
Terminal flag
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10.12 WM 80 Cross Section
7
8
6
9
10
11
5
12
13
4
14
15
16
1
3
2
wc_gr002920
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10.13 WM 80 Cross Section Components
See Graphic: wc_gr002920
Ref
Description
Ref
Description
1
Crankcase
9
Piston
2
Crankcase gasket
10
Piston rings
3
Recoil starter
11
Cylinder
4
Flywheel key
12
Connecting rod
5
Flywheel fan
13
Cylinder gasket
6
Fan hood
14
Crankshaft
7
Retaining ring
15
Shaft seal
8
Piston wrist pin
16
Crankshaft bearing
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10.14 Vacuum Testing Cylinder
See Graphic: wc_gr002940
This procedure requires the use of test kit P/N 0155268, an 1/8 NPT
hose barb, new gaskets, and a vacuum pump.
Note: For clarity, the engine is shown removed from the machine.
10.14.1 Remove the air cleaner or air cleaner duct.
10.14.2 Remove the carburetor. See section Removing Carburetor.
10.14.3 Remove the muffler.
10.14.4 Using the existing nuts, attach a new exhaust gasket (a) and the
exhaust cover (b) over the exhaust port.
10.14.5 Using the existing nuts, attach a new intake gasket (c) and the intake
cover (d) over the intake port. Attach an 1/8-inch NPT hose barb (e) to
the intake cover.
10.14.6 Be sure that the spark plug and all the hardware securing the cylinder
to the crank case is tight.
10.14.7 Attach the vacuum pump (f) to the hose barb. Operate the pump until
1.2–1.7 kPa (5–7 inches) of vacuum is reached. Observe the gauge for
any drop in pressure. A drop of more than 0.25 kPa (1 in.) of vacuum
per minute is considered unacceptable. All leaks should be located
and rectified.
10.14.8 To locate a leak, squirt small amounts of oil around all possible leak
areas. Reapply the vacuum and watch the gauge for a decrease in the
leak rate. Replace the cylinder, hardware, or gaskets as needed.
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b
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10.15 Cylinder and Piston Removal
See Graphic: wc_gr002907
The cylinder and cylinder head is of a one-piece design providing easy
access to the cylinder and piston and eliminating the need for a head
gasket.
The cylinder bore is coated with a wear-resistant metal alloy. This
allows heat to dissipate faster than using a cast iron cylinder sleeve.
The lower operating temperature prevents the oil in the fuel/oil mixture
from dissipating as readily, thus improving engine lubrication.
To remove the cylinder and piston, carry out the following procedure:
10.15.1 Disconnect and remove the spark plug from the engine.
10.15.2 Disconnect the fuel line and the throttle cable from the engine.
10.15.3 Remove the muffler, air filter, and carburetor from the engine. Remove
the engine from the machine.
10.15.4 Remove the four M6 screws (b) holding the cylinder to the crankcase
and remove the cylinder.
10.15.5 Remove the retaining rings (c) securing the piston pin (d) to the piston
(e). Push the pin from the piston and remove the piston from the
connecting rod.
10.15.6 Remove the piston rings (f) from the piston. Be careful not to break the
rings or damage the ring’s grooves when removing the rings.
10.15.7 Remove the needle bearing (g) from the connecting rod.
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f
c
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d
c
g
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10.16 Cylinder and Piston Inspection
See Graphic: wc_gr002908
Ring Gap:
Remove the cylinder from the crankcase. Check the ring gap at the
lower part of the cylinder by placing the ring (h) in the cylinder and
measuring the gap between the ends of the ring. If the ring gap is
greater than 1.2 mm (0.047 in.) the rings need to be replaced. Ring
gaps should measure as follows:
New: 0.2 – 0.4 mm (0.008 – 0.016 in.)
Maximum: 1.0 – 1.2 mm (0.040 – 0.047 in.)
Piston Wear:
Piston wear is checked with a visual inspection. If the piston is
noticeably worn or scored, it should be replaced. Typically, a piston will
last through two sets of rings before requiring replacement.
Cylinder Wear:
Remove the cylinder from the crankcase. Carefully remove any carbon
deposits from the cylinder head, exhaust port, and piston head. Inspect
the piston and cylinder visually for scoring. Check the cylinder coating
for wear. If it has worn through, replace the cylinder.
NOTICE: Do not use a glaze breaker or hone on the cylinder. The
metal alloy coating of the cylinder will be destroyed and render the
cylinder useless.
Measure the cylinder wear by measuring the ring gap at the top of the
cylinder and again at the bottom. Use a new ring if possible and the
same ring for both measurements. If the difference in the two
measurements is greater than 0.2 mm (0.008 in.), the cylinder is worn
beyond its limits. Replace the cylinder, piston, and rings.
Typically, a cylinder will last through two pistons before requiring
replacement.
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10.17 Cylinder and Piston Installation
See Graphic: wc_gr002909
This procedure requires the use of special tool P/N 0031986, ring
compressor. It also requires the use of new retaining rings, P/N
0012257.
10.17.1 Remove all old gasket material from the cylinder and crankcase.
Inspect the mating surfaces of the cylinder and crankcase for any deep
scratches or defects which could prevent a good seal. The cylinder and
crankcase must form an airtight seal for the engine to perform properly.
10.17.2 Install the rings (a) on the piston (b) with the notch in rings facing up,
and around the pins (c) that are located in each groove of the piston.
10.17.3 Install the needle bearing (d) in the connecting rod (e). Position the
piston over the connecting rod with the arrow (f) stamped on the top of
the piston pointing toward the exhaust side of the engine. Slide the
wrist pin (g) in place. Secure the wrist pin with two new retaining rings
(h). Do not re-use old retaining rings.
10.17.4 Position the cylinder gasket (i) on the crankcase and lubricate the
piston rings and cylinder bore with 2-cycle engine oil.
10.17.5 Using ring compressor P/N 0031986 to hold the rings in place,
carefully slide the cylinder over the piston.
10.17.6 Secure the cylinder to the crankcase using M6 screws. Tighten the
screws in the sequence shown and torque to 10 Nm (7 ft.lbs.).
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a
f
b
e
g
h
i
d
2
4
3
1
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10.18 Inspecting Connecting Rod and Crankshaft
See Graphic: wc_gr002910
10.18.1 With the cylinder removed, check the needle bearing (a) for damage or
wear. Replace it if necessary.
10.18.2 Insert the wrist pin into the needle bearing and check for excessive
play. Replay the needle bearing and/or the wrist pin if necessary.
10.18.3 Check the connecting rod (b) for any vertical play—there should be
none. Side play is allowable. If any vertical play is present, the
complete crankshaft assembly must be replaced.
10.18.4 Turn the crankshaft by hand and check that the shaft bearings rotate
freely. Replace worn or damaged bearings.
10.18.5 If a piston ring is broken, inspect the crankcase and bearings to be sure
that no ring pieces have become lodged inside the engine. Flush the
crankcase using an oil-rich fuel mixture.
Note: When replacing the crankshaft, the crankshaft bearings and the
needle bearing for the piston wrist pin must also be replaced.
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OK
OK
b
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10.19 Disassembling Crankcase
See Graphic: wc_gr002911
10.19.1 Remove the clutch, starter, flywheel, cylinder, and piston. Place the nut
back on the shaft to protect shaft threads.
10.19.2 Remove eight M5 screws (a) which secure the crankcase halves
together.
10.19.3 Secure the crankcase in vice or equivalent.
Note: It is suggested that M8 cap screws (b) be screwed into clutch
end of crankcase. Then secure crankcase in vise (c) using the
capscrews.
10.19.4 Heat the area (d) of the crankcase around the bearing using a propane
torch.
10.19.5 While the crankcase is hot, tap firmly on the end of the crankshaft with
a plastic mallet to remove the crankcase from the shaft. Support the
crankcase shell/crankshaft (e) as it slides from the other half of the
crankcase shell. The bearing (f) will remain intact on the shaft.
10.19.6 Support the other half of the crankcase shell/crankshaft. Heat the area
of the crankcase around the bearing using a propane torch.
10.19.7 While the crankcase is hot, tap firmly on the end of the crankshaft with
a plastic mallet to remove the crankshaft (g) from the crankcase shell.
10.19.8 Once the crankcase shell halves have cooled, remove the crankshaft
seals (h) from each shell.
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b
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d
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g
h
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10.20 Assembling Crankcase
See Graphic: wc_gr002912
This procedure requires a propane torch or equivalent heat source.
10.20.1 Lubricate the shaft seals (a) using 2-cycle engine oil. Position one of
the seals over the bore in the crankcase shell (b) with the open side of
the seal facing in. Make sure the seal is laying straight and press it into
the bore, from the outer side, using pusher P/N 0048585. Press until
the outer edge of the seal is flush with the outer edge of the crankcase
shell. In the same manner, press the other shaft seal into the other
crankcase shell (c).
10.20.2 Lubricate both crankshaft bearings with 2-cycle engine oil.
10.20.3 Heat the area (d) of the crankcase shell (b) using a propane torch. Heat
the area to approximately 70°– 80°C (150°–175°F). Be careful not to
damage the seal when heating. Install the crankshaft into the warm
crankcase shell.
Note: The crankshaft should slide easily into the crankcase shell if
heated sufficiently.
10.20.4 Lightly oil gasket (e) with 2-cycle engine oil. Position the gasket over
the roll pins (f) in crankcase shell (c).
10.20.5 Heat crankcase shell (c) using a propane torch (In the same manner
as crankcase shell (b) in step 3.) Heat the area to approximately 70°–
80°C (150°–175°F). Be careful not to damage the seal when heating.
Install the crankshaft into the warm crankcase shell and push the
crankcase shells together until they are tight.
10.20.6 Allow the preassembled crankcase to cool. When cool, secure it
together with M5 screws (g) and nuts (h). Tighten the screws in steps
and torque to 6.5 Nm (5 ft.lbs.).
10.20.7 After the crankcase is assembled, tap it lightly on the end to release
any bearing tension. Check the assembly by turning the crankshaft by
hand. The crankshaft should turn easily.
10.20.8 Trim off any excess gasket material from the outside of the engine and
at the top of the cylinder mounting surface.
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g
f
c
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d
e
a
f
b
h
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10.21 Crankshaft Bearings
See Graphic: wc_gr002913
Press Method Removal:
This procedure requires special tools P/N 0023338, split ring puller (a);
and P/N 0023339, crank support tube (b). It also requires the use of an
Arbor press or equivalent.
10.21.1 Place the two halves of the split ring puller around the bearing on the
crankshaft. If necessary, tap gently on the ring halves to seat them
under the bearing.
10.21.2 Secure the complete assembly in the crank support tube.
10.21.3 Using an Arbor press, press on the end of the crankshaft until the
bearing breaks free.
Note: Support the crankshaft as it slides from the bearing.
Extractor Method Removal:
If a press is not available, the bearings can be pulled from the shaft
using the following special tools: P/N 0013288, extractor (c); P/N
0017328, half shell (d); and P/N 0013290, holding ring (e).
10.21.4 Assemble the tools to the bearing as shown.
10.21.5 Turn the center bolt of the extractor until the bearing breaks free of the
shaft.
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d
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10.22 Bearing Installation
See Graphic: wc_gr002914
This procedure requires special tools P/N 0048585, pusher tube (f);
P/N 0032028, crank support plate (g); and P/N 0023339 crank support
tube (h).
10.22.1 Slide the support plate between the counterweights at the center of the
crankshaft as far as possible, then place it on the support tube so that
the counterweight on the crankshaft is fully supported.
10.22.2 Lubricate the inner bearing race and the crankshaft using 2-cycle
engine oil.
10.22.3 Using the pusher tube, press the bearing onto the crankshaft until the
bearing rests against the shoulder of the crankshaft.
NOTICE: When pressing, press only on the inner bearing race.
Pressing on any other surface of the bearing may damage the bearing.
NOTICE: Failure to support the crankshaft properly while installing the
bearings may cause the shaft to break.
f
g
h
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Wacker Neuson SE
·
Preußenstraße 41
· D-80809 München
· Tel.: +49-(0)89-3 54 02-0 · Fax: +49 - (0)89-3 54 02-390
Wacker Neuson Corporation · N92W15000 Anthony Ave. · Menomonee Falls, WI 53051 · Tel. : (262) 255-0500 · Fax: (262) 255-0550 ·Tel. : (800) 770-0957
Wacker Neuson Limited - Room 1701–03 & 1717–20, 17/F. Tower 1, Grand Century Place, 193 Prince Edward Road West, Mongkok, Kowloon, Hongkong.
Tel: (852) 3605 5360, Fax: (852) 2758 0032
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