Honda WDP30X Instructions Manual

A FEW WORDS ABOUT SAFETY
SERVICE INFORMATION
The service and repair information contained in this manual is intended for use by qualified, professional technicians. Attempting
service or repairs without the proper training, tools, and equipment could cause injury to you or others. It could also damage the
water pump or create an unsafe condition.
This manual describes the proper methods and procedures for performing service, maintenance, and repairs. Some procedures
require the use of special tools. Any person who intends to use a replacement part, service procedure, or a tool that is not
recommended by Honda, must determine the risks to their personal safety and the safe operation of the pump.
If you need to replace a part, use Honda Genuine parts with the correct part number, or an equivalent part. We strongly recommend
that you do not use replacement parts of inferior quality.
For Your Customer’s Safety
Proper service and maintenance are essential to the customer’s safety and the
reliability of the pump. Any error or oversight while servicing a pump can result
in faulty operation, damage to the pump, or injury to others.
For Your Safety
Because this manual is intended for the professional service technician, we do
not provide warnings about many basic shop safety practices (e.g., Hot parts –
wear gloves). If you have not received shop safety training or do not feel
confident about your knowledge of safe servicing practices, we recommend that
you do not attempt to perform the procedures described in this manual.
Some of the most important general service safety precautions are given below.
However, we cannot warn you of every conceivable hazard that can arise in
performing service and repair procedures. Only you can decide whether or not
you should perform a given task.
WARNING
Improper service or repairs can create an unsafe
condition that can cause your customer or others
to be seriously hurt or killed.
Follow the procedures and precautions in this
manual and other service materials carefully.
WARNING
Failure to properly follow instructions and
precautions can cause you to be seriously hurt
or killed.
Follow the procedures and precautions in this
manual carefully.
Important Safety Precautions
• Make sure you have a clear understanding of all basic shop safety practices
and that you are wearing appropriate clothing and using safety equipment. When performing any service task, be especially careful
of the following:
 Read all of the instructions before you begin, and make sure you have the tools, the replacement or repair parts, and the skills
required to perform the tasks safely and completely.
 Protect your eyes by using proper safety glasses, goggles, or face shields anytime you hammer, drill, grind, or work around
pressurized air or liquids, and springs or other stored-energy components. If there is any doubt, put on eye protection.
 Use other protective wear when necessary, for example, gloves or safety shoes. Handling hot or sharp parts can cause severe
burns or cuts. Before you grab something that looks like it can hurt you, stop and put on gloves.
• Make sure the engine is off before you begin any servicing procedures, unless the instructions tell you to do otherwise. This will
help eliminate several potential hazards:
 Carbon monoxide poisoning from engine exhaust. Be sure there is adequate ventilation whenever you run the engine.
 Burns from hot parts. Let the engine and exhaust system cool before working in those areas.
 Injury from moving parts. If the instruction tells you to run the engine, be sure your hands, fingers, and clothing are out of the
way.
• Gasoline vapors are explosive. To reduce the possibility of a fire or explosion, be careful when working around gasoline.
 Use only a nonflammable solvent, not gasoline, to clean parts.
 Never drain or store gasoline in an open container.
 Keep all cigarettes, sparks, and flames away from all fuel-related parts.
WDP30X
INTRODUCTION
CONTENTS
This manual covers service and repair procedures for the
Honda WDP30X, K1, and K2 diaphragm pumps.
SPECIFICATIONS
1
All information contained in this manual is based on the latest
product information available at the time of printing. We
reserve the right to make changes at any time without notice.
SERVICE INFORMATION
2
MAINTENANCE
3
AIR CLEANER/CARBURETOR
4
RECOIL STARTER/FUEL TANK
5
MUFFLER
6
STARTER PULLEY/IGNITION COIL/
FLYWHEEL
7
CAM PULLEY/LOWER CRANKCASE
8
CRANKSHAFT/PISTON/
CYLINDER BLOCK/VALVES
9
No part of this publication may be reproduced, stored in a
retrieval system, or transmitted, in any form by any means,
electronic, mechanical, photocopying, recording, or
otherwise, without prior written permission of the publisher.
This includes text, figures, and tables.
As you read this manual, you will find information that is
preceded by a NOTICE symbol. The purpose of this
message is to help prevent damage to the pump, other
property, or the environment.
SAFETY MESSAGES
Your safety and the safety of others are very important. To
help you make informed decisions, we have provided safety
messages and other safety information throughout this
manual. Of course, it is not practical or possible to warn you
about all the hazards associated with servicing this pump.
You must use your own good judgement.
You will find important safety information in a variety of forms,
including:
• Safety Labels – on the pump.
• Safety Messages – preceded by a safety alert symbol
and one of three signal words: DANGER, WARNING, or
CAUTION.
These signal words mean:
 DANGER
You WILL be KILLED or
SERIOUSLY HURT if you don’t
follow instructions.
 WARNING
You CAN be KILLED or
SERIOUSLY HURT if you don’t
follow instructions.
 CAUTION
You CAN be HURT if you don’t
follow instructions.
CASE/DIAPHRAGM
10
GEARBOX
11
FRAME/WHEELS
12
INDEX
13
• Instructions – how to service this pump correctly and
safely.
American Honda Motor Co., Inc.
Service Communications Department
Revised: April 2012 (PSV61TDP00E2)
i
WDP30X
ii
Revised: April 2012 (PSV61TDP00E2)
1. SPECIFICATIONS
WDP30X
1. SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . 1-1
3. DIMENSIONAL DRAWINGS . . . . . . . . . . . . . . . 1-4
2. PERFORMANCE CURVE . . . . . . . . . . . . . . . . . 1-3
4. WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . 1-5
1. SPECIFICATIONS
• DIMENSIONS, WEIGHTS, AND CAPACITIES
Model
WDP30X
Type
WDP30XK1
WDP30XK2
AT
Description code
WZCA
Overall length
826 mm (32.5 in)
800 mm (31.5 in)
Overall width
594 mm (23.4 in)
775 mm (30.5 in)
Overall height
635 mm (25.0 in)
654 mm (25.7 in)
Dry weight
54.4 kg (120 lbs)
73.9 kg (163 lbs)
Fuel tank capacity
2.0  (0.53 US gal)
Engine oil capacity
0.56  (0.59 US qt)
• WATER PUMP
Type
Diaphragm with spring-type connecting rod
Suction port diameter
3 in NPT
Discharge port diameter
3 in NPT
Maximum total head
15 m (50 ft)
Maximum suction head (dry)
4.9 m (16 ft)
Maximum suction head
(after priming pump housing)
7.3 m (24 ft)
Maximum discharge capacity
302 /min (80 gpm)
Self-priming time
Maximum solid size
Diaphragm
Valves
20 sec. at 6.1 m (20 ft)
60 mm (2.4 in)
Neoprene with nylon cloth
Neoprene with cast iron inserts
• GEARBOX
Pump operating frequency
Gear reduction
73 strokes/min @ 3,150 rpm
43:1
Pump stroke
70.4 mm (2.77 in)
Gearbox oil capacity
0.8  (0.8 US qt)
Revised:
April 2012
Date of Issue:
April (PSV61TDP00E2)
2008
1-1
WDP30X
• ENGINE
Engine model
Description code
Engine type
GX120K1QX2
GX120UT1QX2
GX120UT2QX2
GCAAT
GCAGT
GCBMT
4-stroke, overhead-valve, single-cylinder inclined by 25°
Displacement
118 cm³ (7.2 cu in)
Bore x stroke
60 x 42 mm (2.4 x 1.7 in)
Compression ratio
8.5: 1
3,000 ~ 3,150 min-1 (rpm)
Maximum governed speed
Ignition system
Ignition timing
Spark plug
Lubrication system
Oil capacity
Transistorized magneto ignition
25° B.T.D.C.(fixed)
20 + 3° B.T.D.C.
300 ~ 4,200 min-1 (rpm)
BPR6ES (NGK)
Splash type
0.56  (0.59 US qt)
Cooling system
Forced air
Starting system
Recoil starter
Stopping system
Ignition primary circuit ground
Carburetor
Horizontal-type, butterfly valve
Air cleaner
Dual element type
Fuel used
Unleaded gasoline with a pump octane number 86 or higher
Fuel tank capacity
1-2
2.0  (0.53 US gal)
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
WDP30X
TOTAL HEAD
2. PERFORMANCE CURVE
(m)
(ft)
15.2
50
12.2
40
9.1
30
6.1
20
3.0
10
0
40
50
60
70
80
90
151
189
227
264
303
341
(US gal/min)
(/min)
DISCHARGE CAPACITY
Pump Priming
Pump priming is not required if the vertical distance from water to the pump (suction head) is less than 16 feet.
The suction head can be increased to 24 feet if the pump is primed.
Date of Issue: April 2008
1-3
WDP30X
3. DIMENSIONAL DRAWINGS
635 mm (25.0 in)
WDP30X
82
6
594 mm (23.4 in)
m
m
(3
2.
5
in
)
WDP30XK1, K2
654 mm (25.7 in)
755 mm (30.5 in)
80
0m
m(
31
.5
in
)
Dimensions are with the handlebar installed over the engine.
1-4
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
WDP30X
4. WIRING DIAGRAM
IGNITION CONTROL
MODULE
IGNITION
SWITCH
Y
BL
SPARK
PLUG
Y
BL
OIL ALERT
UNIT
OIL LEVEL
SWITCH
Date of Issue: April 2008
BL
BLACK
Y
YELLOW
1-5
WDP30X
1-6
Date of Issue: April 2008
2. SERVICE INFORMATION
WDP30X
1. SERVICE RULES . . . . . . . . . . . . . . . . . . . . . . . . 2-1
5. TORQUE VALUES . . . . . . . . . . . . . . . . . . . . . . . 2-4
2. SYMBOLS USED IN THIS MANUAL. . . . . . . . . 2-1
6. TOOLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
3. SERIAL NUMBER LOCATIONS . . . . . . . . . . . . 2-2
7. TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . 2-7
4. MAINTENANCE STANDARDS . . . . . . . . . . . . . 2-3
1. SERVICE RULES
• Use Honda Genuine parts or their exact equivalent. Lower quality parts can damage the pump or reduce its
performance.
•
• Install new gaskets, O-rings, and seals during assembly.
• This pump uses metric fasteners and SAE (nonmetric) fasteners. Metric bolts, nuts, and screws are not
interchangeable with nonmetric fasteners. The use of incorrect tools and fasteners may damage the pump.
• When tightening nuts and bolts, begin with the larger-diameter or inner bolts, and tighten diagonally to the specified
torque values, unless a particular tightening sequence is specified.
• When tightening self-tapping screws, be especially careful to avoid cross-threading or overtightening.
• Clean parts in nonflammable solvent after disassembly.
• Lubricate sliding surfaces before assembly.
• After assembly, check parts installation and operation.
2. SYMBOLS USED IN THIS MANUAL
As you read this manual, you may find the following symbols with the instructions.

(Commercially
available)


O x O (O)
P. O-O
A special tool is required to perform the procedure.
Commercially available tools are distinguished by the words (commercially available). They are
not available through the American Honda Parts Department. Most commercially available tools
shown in this shop manual can be ordered through the Honda Power Equipment (P/E) Tool and
Equipment program by calling (888) 424-6857. Refer to the Tool and Equipment program
catalog for a complete tool listing.
Apply grease
Apply oil
x () Indicates the diameter, length, and quantity of metric flange bolts used.
P. - Indicates the reference page.
Date of Issue: April 2008
2-1
WDP30X
3. SERIAL NUMBER LOCATIONS
There are two serial numbers, one for the engine and one for the frame.
Always refer to these numbers when ordering parts and when making technical inquiries.
FRAME SERIAL NUMBER
ENGINE SERIAL NUMBER
2-2
Date of Issue: April 2008
WDP30X
4. MAINTENANCE STANDARDS
PART
ITEM
STANDARD
SERVICE LIMIT
Engine
Maximum governed speed
Idle speed
Cylinder compression
3,000 ~ 3,150 rpm
1,400 +200/-150 rpm
6.0 ~ 8.5 kg/cm2 (85 ~ 121 psi) at 600 rpm
-------------------------------------------------------------------
Carburetor
Main jet
Float height
Pilot screw opening
#60
13.7 mm
1-5/8 turns out
------------------------------------------------------------------
Spark plug
Gap
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
-----------------------
Spark plug cap
Resistance
7.5 ~ 12.5 k
-----------------------
0.15 ± 0.02 mm
0.20 ± 0.02 mm
5.48 mm
5.44 mm
5.50 mm
0.02 ~ 0.044 mm
0.06 ~ 0.087 mm
0.8 mm
30.5 mm
(0.216 in)
(0.214 in)
(0.217 in)
(0.0008 ~ 0.0017 in)
(0.0024 ~ 0.0034 in)
(0.031 in)
(1.200 in)
--------------------------------------------5.318 mm (0.2094 in)
5.275 mm (0.2077 in)
5.572 mm (0.2194 in)
0.10 mm
(0.004 in)
0.12 mm
(0.005 in)
2.0 mm
(0.07 in)
29.0 mm
(1.28 in)
Skirt OD
Piston-to-cylinder clearance
Piston pin bore ID
Pin OD
Piston-to-piston pin bore
clearance
59.985 mm
0.015 ~ 0.060 mm
13.002 mm
13.000 mm
(2.3616 in)
(0.0006 ~ 0.0024 in)
(0.5119 in)
(0.5118 in)
59.845 mm
0.12 mm
13.048 mm
12.954 mm
(2.3561 in)
(0.005 in)
(0.5137 in)
(0.5100 in)
0.002 ~ 0.014 mm (0.0001 ~ 0.0006 in)
0.08 mm
(0.003 in)
Ring width
1.5 mm
2.5 mm
1.37 mm
2.37 mm
(0.054 in)
(0.093 in)
Valve clearance (cold)
Stem OD
Valves
Guide ID
Stem clearance
IN
EX
IN
EX
IN/EX
IN
EX
Seat width
Spring free length
Piston
Piston rings
(GX120K1QX2)
Ring side
clearance
Ring end
gap
Top/Second
Oil
(0.06 in)
(0.10 in)
Top/Second/Oil
Top/Second
Oil
0.015 ~ 0.045 mm (0.0006 ~ 0.0018 in)
0.15 ~ 0.35 mm
(0.006 ~ 0.014 in)
0.15 ~ 0.35 mm
(0.006 ~ 0.014 in)
0.15 mm
1.0 mm
1.0 mm
(0.006 in)
(0.039 in)
(0.039 in)
Top
Second
Top
Second
Top
Second
Oil (side rail)
0.95 ~ 0.97 mm
(0.037 ~ 0.038 in)
0.94 ~ 0.96 mm
(0.037 ~ 0.038 in)
0.035 ~ 0.070 mm) (0.0014~0.0028 in)
0.045 ~ 0.080 mm (0.0018 ~ 0.0031 in)
0.20 ~ 0.35 mm) (0.008 ~ 0.014 in)
0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)
0.20 ~ 0.70 mm) (0.008 ~ 0.028 in)
0.93 mm
0.92 mm
0.150 mm
0.150 mm
1.0 mm
1.0 mm
1.0 mm
(0.037 in)
(0.036 in)
(0.0059 in)
(0.0059 in)
(0.04 in)
(0.04 in)
(0.04 in)
60.00 mm
60.165 mm (2.3687 in)
Ring width
Piston rings
(GX120UT1QX2,
GX120UT2QX2)
Ring side
clearance
Ring end
gap
Cylinder
Sleeve ID
Cylinder head
Warpage
Connecting rod
Small end ID
Big end ID
Big end oil clearance
Big end axial clearance
13.005 mm
26.02 mm
0.040 ~ 0.063 mm
0.1 ~ 0.4 mm
Crankshaft
Crankshaft O.D.
(2.36 in)
0.10 mm
(0.004 in)
(0.5120 in)
(1.0240 in)
(0.0016 ~ 0.0025 in)
(0.004 ~ 0.016 in)
13.07 mm
26.066 mm
0.12 mm
1.1 mm
(0.515 in)
(1.0262 in)
(0.005 in)
(0.043 in)
25.98 mm
(1.023 in)
25.92 mm (1.020 in)
Camshaft O.D.
27.7 mm
27.75 mm
13.984 mm
(1.090 in)
(1.0925 in)
(0.5506 in)
27.45 mm (1.081 in)
27.50 mm (1.083 in)
13.916 mm (0.5479 in)
Resistance
Primary coil
Secondary coil (cap removed)
Air gap
(at flywheel)
0.8 ~ 1.0 
5.9 ~ 7.1 k
0.4 ± 0.2 mm
Cam height
Camshaft
Ignition coil
(0.54 in)
Revised:
April 2012
(PSV61TDP00E2)
Date of Issue:
April 2008
-----------------------
IN
EX
(0.016 ± 0.008 in)
-------------------------------------------------------------------
2-3
WDP30X
5. TORQUE VALUES
TORQUE
THREAD DIAMETER x
PITCH mm
N•m
kg-m
ft-lb
Connecting rod bolt
7 x 1.0
12
1.2
8.7
Cylinder head bolt
8 x 1.25
24
2.4
18
14 x 1.5 (special)
74
7.5
55
6 x 0.5
10
1.0
7
Rocker arm pivot stud
8 x 1.25 (special)
24
2.4
18
Crankcase cover bolt
6 x 1.0 (CT)
12
1.2
9
Air cleaner wing nut
6 x 1.0
9
0.9
6.5
Muffler mounting nut
8 x 1.25
24
2.4
18
Oil drain bolt
10 x 1.25
18
1.8
13
Fuel tank flange nut
6 x 1.0
10
1.0
7
Sediment cup
24 x 1.0
3.9
0.4
2.9
Diaphragm connecting rod
bolt
10 x 1.5
54
5.4
40
Diaphragm upper case nut
12 x 1.75
47
4.7
35
Diaphragm connecting rod
nut
12 x 1.75
47
4.7
35
5/16-18 x 1.5 in
19
2
14
SPECIAL FASTENERS
Flywheel nut
Rocker arm pivot lock nut
Engine mounting bolt
Use standard torque values for fasteners that are not listed above.
(CT) Indicates a self-tapping bolt.
STANDARD TORQUE VALUES
STANDARD FASTENERS
Screw
Bolt and nut
Flange bolt and nut
2-4
THREAD DIAMETER
TORQUE
N•m
kg-m
ft-lb
5 mm
3.9
0.4
2.9
6 mm
8.8
0.9
6.5
5 mm
4.9
0.5
3.6
6 mm
9.8
1.0
7.2
8 mm
21
2.1
15
10 mm
34
3.5
25
12 mm
54
5.5
40
6 mm
12
1.2
8.7
8 mm
26
2.7
20
10 mm
39
4.0
29
Date of Issue: April 2008
WDP30X
6. TOOLS
a. SPECIAL
ITEM
TOOL NAME
TOOL NUMBER
APPLICATION
1
Carburetor float level gauge
07401-0010000
Carburetor float level inspection
2
Attachment, 52 x 55 mm
07746-00010400
Crankshaft bearing 6205, 62/22 installation
3
Driver, 40 mm ID
07746-0030100
Driver for attachments 4 and 5
4
Attachment, 25 mm ID
07746-0030200
Timing gear installation
5
Attachment, 30 mm ID
07746-0030300
Governor drive gear installation
6
Pilot, 22 mm ID
07746-0040100
Crankshaft bearing 62/22 installation
7
Driver
07749-0010000
Driver for tool 2
8
Valve guide driver, 5.5 mm
07942-8920000
Valve guide removal/installation
9
Valve guide reamer, 5.5 mm
07984-200000D
Valve guide ID reaming
Date of Issue: April 2008
2-5
WDP30X
b. COMMERCIALLY AVAILABLE
ITEM
TOOL NAME
1
Compression gauge
2
TOOL NUMBER
APPLICATION
SUN-EEP-V303A
Compression test
Strap wrench
STV-S-17
Flywheel removal
3
Flywheel puller
OTC-1035
Flywheel removal
4
Digital multimeter
5
Combustion chamber cleaning
brush and drill extension
FLU-88
Electrical component testing
Procured locally
Clean combustion chamber
6A
Valve seat cutter, 31°
NWY CU 115
6B
Valve seat cutter, 45°
NWY CU 122
6C
Valve seat cutter, 60°
NWY CU 111
6D
Solid pilot bar, 5.50 mm
NWY PM 10055SH
6E
Solid pilot bar, 5.51 mm
NWY PM 100552S
6F
T-wrench, #505
6G
T-wrench adaptor, #503-1
NWY TW 503-1
6H
T-wrench extension, 6 in
NWY TW 503-6H
6I
Accessory package #246
NWY KACC 246
Valve seat reconditioning
NWY TW 505
2
1
3
5
AUTOMOTIVE METER
4
D E
ZERO
MIN MAX
RANGE
RPM
%DUTY
ALERT
ms-PULSE
+ TRIGGER
-
SMOOTH
Hz
mV
V
F
H
I
HOLD H
6
A
31°
mA
A
RPM
mA
A
V
B
45°
OFF
A
mA
10A MAX
FUSED
COM
400mA MAX
FUSED
!
V
RPM
1000V MAX
C
60°
G
Commercially available tools are distinguished by the words (commercially available). They are not available through
the American Honda Parts Department. Most commercially available tools shown in this shop manual can be ordered
through the Honda Power Equipment (P/E) Tool and Equipment program by calling (888) 424-6857. Refer to the Tool
and Equipment program catalog for a complete tool listing.
2-6
Date of Issue: April 2008
WDP30X
7. TROUBLESHOOTING
a. HARD STARTING
1. Check fuel level.
NO FUEL IN TANK
Refuel.
SUFFICIENT FUEL IN TANK
2. Remove spark plug and inspect
(P. 3-5).
WET
• Clean and install plug, then
restart engine.
• Check carburetor for flooding.
DRY
3. Check spark plug operation
(P. 2-8).
WEAK OR NO SPARK
• See IGNITION SYSTEM
TROUBLESHOOTING (P. 2-8).
• Check ignition coil air gap
(P. 7-2).
GOOD SPARK
4. Check choke adjustment or
throttle adjustment (P. 3-8).
CHOKE PARTIALLY OPEN
Adjust cable/linkage to close
choke.
CHOKE CLOSED
5. Compression check (see below).
ABNORMAL COMPRESSION
NORMAL COMPRESSION
• Check for incorrect valve
clearance.
• Check for heavy carbon deposits
in combustion chamber.
• Check for defective valves or
valve seats.
• Check for worn piston rings,
piston, or cylinder.
6. Remove and clean carburetor
(P. 4-3).
7. Install spark plug and restart
engine.
• COMPRESSION TEST
1. Remove the spark plug and install a compression gauge
(commercially available) in the spark plug hole.
2. Pull the recoil starter several times with the recoil starter
and measure cylinder compression.
Compression
Date of Issue: April 2008
COMPRESSION GAUGE
(Commercially available)
6.0 ~ 8.5 kg/cm2 (85 ~ 121 psi)
at 600 rpm
2-7
WDP30X
b. IGNITION SYSTEM
Engine does not start with the
ignition switch in the ON position.
1. Test the spark plug (see below).
NO SPARK
2. Check again with a new spark
plug.
SPARKS
• Faulty spark plug.
• Install new spark plug (P. 3-5).
SPARKS
• Faulty engine stop switch.
• Replace the engine stop switch
(P. 5-4).
NO SPARK
3. Disconnect the black wire from
the engine stop switch and
recheck.
NO SPARK
• Defective ignition coil.
• Replace the ignition coil (P. 7-1).
• SPARK TEST
1. Remove the spark plug, attach it to the spark plug cap,
and ground the side electrode against the cylinder head
cover.
2. Turn the ignition switch to the ON position. Pull the
starter grip and check to see if sparks jump across the
electrodes.
 WARNING
Gasoline is highly flammable and explosive. If ignited,
gasoline can burn you severely.
Before testing the spark plug:
•
•
•
•
2-8
Be sure there is no spilled fuel near the engine.
Place the spark plug away from the spark plug hole.
Unburnt gas can ignite if it is left in the cylinder.
Loosen the carburetor drain screw to drain the
carburetor thoroughly. Pull the recoil starter several
times to release the unburnt gas from the cylinder
before test.
Date of Issue: April 2008
WDP30X
c. PUMP
Not self priming
1. Strainer
CLOGGED/DAMAGED
Clean or replace strainer.
OK
2. Suction head
TOO GREAT
Move pump closer to the water
(P. 1-3).
OK
3. Suction hose
CLOGGED/DAMAGED
Clean or replace hose.
OK
4. Couplings
AIR LEAKS
Tighten couplings.
DAMAGED
Install wear plate and gasket or
replace clappet valve (P. 10-1).
TOO GREAT
Move pump closer to the water
(P. 1-3).
OK
5. Clappet valve
Discharge volume or pressure
is too low.
1. Suction head
OK
2. Strainer
CLOGGED/DAMAGED
Clean or replace strainer.
OK
3. Pump RPM
TOO LOW
Adjust throttle lever.
TOO HIGH
Reduce the total head (P. 1-3).
TOO LONG OR
I.D. TOO SMALL
Reduce hose length or increase
hose I.D.
OK
4. Total head
OK
5. Discharge hose
Date of Issue: April 2008
2-9
WDP30X
2-10
Date of Issue: April 2008
3. MAINTENANCE
WDP30X
1. MAINTENANCE SCHEDULE. . . . . . . . . . . . . . . 3-1
7. VALVE CLEARANCE . . . . . . . . . . . . . . . . . . . . . 3-7
2. ENGINE OIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
8. IDLE SPEED. . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
3. PUMP GEARBOX . . . . . . . . . . . . . . . . . . . . . . . 3-3
9. FUEL STRAINER CUP. . . . . . . . . . . . . . . . . . . . 3-8
4. AIR CLEANER . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
10. FUEL TANK & FUEL FILTER. . . . . . . . . . . . . . . 3-9
5. SPARK PLUG. . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
11. GOVERNOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
6. SPARK ARRESTER (OPTIONAL PART) . . . . . 3-6
12. PUMP CLAPPET VALVE . . . . . . . . . . . . . . . . . 3-10
1. MAINTENANCE SCHEDULE
REGULAR SERVICE PERIOD (1)
ITEM
Perform at every
indicated interval.
Engine oil
Check
Before
each
use
After
each
use
Check
Every
Every
3 months 6 months
or 50
or 100
hours
hours
O (2)
O (2)
O (2)
Check
Flush
Pump connecting
rod bearing
Grease
Fuel strainer cup
Clean
Gearbox oil
Check level
O (2)
O
—
O
—
O
O
P. 3-3
O
Check-Adjust
P. 3-8
O
Change
Spark plug
P. 3-2
P. 3-4
Replace paper filter
Pump chamber
O (2)
Refer
to
page
O
Clean
Hoses and strainer
Every
year or
300
hours
O
Change
Air cleaner
First
month
or 20
hours
O
O
Replace
O
P. 3-3
P. 3-5
Spark arrester
(optional part)
Clean
Valve clearance
Check-Adjust
O (3)
P. 3-7
Idle speed
Check-Adjust
O (3)
P. 3-8
Pump clappet valve
Inspect
O
P. 3-10
O
P. 3-6
Pump diaphragm
Inspect
O
P. 10-3
Nuts and bolts
Check torque
O
P. 2-4
Fuel tank and filter
Clean
Fuel line
Check
O (3)
Every 2 years (Replace if necessary) (3)
P. 5-5
(1) Log hours of operation to determine proper maintenance intervals.
(2) Service more frequently when used in dusty areas.
(3) These items should be serviced by an authorized Honda servicing dealer, unless you have the proper tools and are
mechanically proficient.
Date of Issue: April 2008
3-1
WDP30X
2. ENGINE OIL
a. INSPECTION
1. Remove the oil filler cap, and wipe the dipstick clean.
2. Insert the dipstick in the oil filler neck, but do not screw it in.
Remove the dipstick and check the oil level.
3. Add the recommended oil to the upper limit mark on the
dipstick, with the dipstick fully inserted but not screwed in.
Do not overfill.
4. Tighten the oil filler cap securely.
FILLER CAP/
DIPSTICK
DRAIN BOLT
b. OIL CHANGE
Change the engine oil while the engine is warm and in a
horizontal position to assure complete and rapid draining.
1. Remove the oil filler cap/dipstick and the drain bolt. Allow
the oil to drain completely.
2. Reinstall the drain bolt, and tighten to the specified torque.
TORQUE: 18 N•m (13 ft•lb)
3. Please dispose of used motor oil in a manner that is
compatible with the environment. We suggest you take
used oil in a sealed container to your local recycling center
or service station for reclamation. Do not throw it in the trash
or pour it on the ground or down a drain.
FILLER CAP/
DIPSTICK
DRAIN BOLT
 CAUTION
Used engine oil contains substances that have been
identified as carcinogenic.
If repeatedly left in contact with the skin for prolonged
periods, it may cause skin cancer.
Wash your hands thoroughly with soap and water as
soon as possible after contact with used engine oil.
4. Refill with the recommended oil to the upper limit mark on
the dipstick. Check oil level with the pump on a level
surface, and the dipstick fully inserted but not screwed in.
Engine oil capacity
OIL
FILLER
NECK
0.56  (0.59 US qt)
Oil is a major factor affecting performance and service life.
Use 4-stroke automotive detergent oil.
SAE 10W-30 API service category SJ or later is
recommended for general use. Other viscosities shown in
the chart may be used when the average temperature in
your area is within the recommended range.
–20
–30
0
–20
20
–10
40
0
60
10
1000F
80
20
30
400C
AMBIENT TEMPERATURE
3-2
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
WDP30X
3. PUMP GEARBOX
SERVICE BULLETIN #7
a. CONNECTING ROD GREASE
PLASTIC
ACCESS COVER
Remove the plastic access plug. Disconnect the spark plug cap
and pull the starter grip until the grease nipple is visible in the
access opening.
Wipe the grease nipple to prevent dirt from getting into the
bearing and using a manual grease gun, pump one or two
strokes of general purpose grease into the bearing.
Recommended grease
NLGI #2
Reinstall the access plug and connect the spark plug cap.
b. OIL LEVEL CHECK
Check the gearbox oil level with the engine stopped and on a
level surface.
CONNECTING
ROD COVER
S/N WZCA-6000001~6000824: Remove the oil plug and check
that the oil level is to the bottom of the oil plug.
8 x 15 mm
BOLT and
WASHER (2)
S/N WZCA-6000825 ~ later: Remove the oil filler cap/dipstick
and check that the oil level is at the upper limit mark on the
dipstick.
Recommended oil
OIL FILLER
CAP/DIPSTICK
SAE 80W-90
GL5 gear oil
OIL PLUG
c. OIL CHANGE
Change the gearbox oil while the gearbox is warm to assure
complete and rapid draining.
Remove the two 8 x 15 mm bolts and washers from the
connecting rod cover.
Place a suitable container under the gearcase and remove the
drain bolt from the lower end of the gearbox.
OIL FILLER
CAP/
DIPSTICK
UPPER
LIMIT
LOWER
LIMIT
WASHER
Replace the drain bolt and washer and fill the gearbox as
described above.
Gearbox capacity
0.8  (0.8 US qt)
WASHER
DRAIN BOLT
NOTICE
Avoid getting gear oil on the diaphragm. Drain oil into a drain
pan to prevent oil from running down the pump case onto the
diaphragm. If gear oil comes in contact with the diaphragm, it
will be damaged.
Date of Issue: April 2008
3-3
WDP30X
4. AIR CLEANER
CLEANING
A dirty air filter will restrict air flow to the carburetor, reducing
engine performance. If the engine is operated in dusty areas,
clean the air filter more often than specified in the
MAINTENANCE SCHEDULE.
NOTICE
Operating the engine without an air filter or with a damaged
air filter will allow dirt to enter the engine, causing rapid
engine wear. This type of damage is not covered by the
DISTRIBUTOR’S LIMITED WARRANTY.
1. Remove the air cleaner cover nut and then remove the air
cleaner cover.
2. Loosen the wing nut and remove the air cleaner elements
and the air cleaner elbow packing. Separate the elements
and carefully check them for holes or tears and replace if
damaged. Check the air cleaner elbow packing for
deterioration or damage.
3. Foam element:
Clean the element in warm soapy water, rinse and allow to
dry thoroughly, or clean with a high flash point solvent and
allow to dry thoroughly. Dip the element in clean engine oil
and squeeze out all the excess oil.
Excess oil will restrict air flow through the foam element
and may cause the engine to smoke at startup.
4. Paper element:
Tap the element lightly several times on a hard surface to
remove excess dirt or blow compressed air [207 kPa
(30 psi or less)] through the filter from the inside out.
Never try to brush the dirt off; brushing will force dirt into
the fibers.
AIR CLEANER
COVER NUT
AIR CLEANER
COVER
WING NUT
AIR CLEANER
FOAM AND
PAPER
ELEMENTS
AIR CLEANER
ELBOW PACKING
FOAM ELEMENT
SOLVENT
ENGINE OIL
SQUEEZE THOROUGHLY
PAPER ELEMENT
5. Wipe dirt from the inside of the air cleaner housing and
cover, using a moist rag. Be careful to prevent dirt from
entering the air duct leading to the carburetor.
6. Reinstall the air cleaner elbow packing and the air cleaner
elements. Tighten the wing nut.
7. Reinstall the air cleaner cover and tighten the nut.
3-4
Date of Issue: April 2008
WDP30X
5. SPARK PLUG
INSPECTION
Recommended spark plug
NGK
BPR6ES
NOTICE
An incorrect spark plug can cause engine damage. Use the
recommended spark plug or an exact equivalent.
1. Visually inspect the spark plug. Discard the plug if the
insulator is cracked or chipped.
2. Measure the plug gap with a wire-type gauge. If
necessary, adjust the gap by bending the side electrode.
Spark plug gap
0.7~ 0.8 mm
(0.028 ~ 0.031 in)
0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
3. Make sure the sealing washer is in good condition and
replace if necessary.
4. Install the plug finger-tight to seat the washer, then tighten
with a plug wrench.
New plug: tighten 1/2 turn after the sealing washer seats.
SEALING
WASHER
Reused plug: tighten 1/8 ~ 1/4 turn after the washer seats.
NOTICE
A loose spark plug can overheat and damage the engine.
Overtightening can damage the threads in the cylinder
head.
5. Install the spark plug cap.
Date of Issue: April 2008
3-5
WDP30X
6. SPARK ARRESTER (OPTIONAL
PART)
If the engine has been running, the muffler will be very hot.
Allow the muffler to cool before servicing the spark arrester.
MUFFLER
PROTECTOR
CLEANING
4 mm
SCREW
The spark arrester must be serviced every 100 hours to keep
it functioning as designed.
1. Remove the two 8 mm nuts and remove the muffler from
the cylinder head.
2. Remove the 4 mm screw from the spark arrester and
remove the spark arrester from the muffler.
3. Use a stiff brush to remove carbon deposits from the
spark arrester screen. Be careful not to damage the spark
arrester screen.
4. Inspect the spark arrester for breaks and holes. Replace if
necessary.
5. Install the spark arrester and muffler in the reverse order
of removal.
5 mm SCREW (4)
8 mm NUT (2)
SPARK
ARRESTER
MUFFLER
SPARK ARRESTER
SCREEN
3-6
Date of Issue: April 2008
WDP30X
7. VALVE CLEARANCE
CYLINDER HEAD COVER
CYLINDER HEAD
COVER GASKET
INSPECTION/ADJUSTMENT
Valve clearance inspection and adjustment must be
performed with the engine cold.
1. Remove the four cylinder head cover bolts, cylinder head
cover gasket, and cover.
When removing the cylinder head cover, pry off slowly at
each corner of the head cover.
CYLINDER HEAD BOLT (4)
NOTICE
Using too much force can deform the cylinder head cover.
The cylinder head cover must be replaced if it is
deformed.
TOP HOLE
ALIGN
2. Set the piston at top dead center of the compression
stroke (both valves fully closed). The triangular mark on
the starter pulley will align with the top hole on the fan
cover when the piston is at top dead center of the
compression stroke and the exhaust stroke.
TRIANGLE MARK
3. Insert a feeler gauge between the rocker arm and the
valve to measure valve clearance.
Standard valve clearance
(cold)
IN
0.15 ± 0.02 mm
EX
0.20 ± 0.02 mm
FEELER GAUGE
4. If adjustment is necessary:
a. Hold the rocker arm pivot and loosen the rocker arm
pivot lock nut.
b. Turn the rocker arm pivot to obtain the specified
clearance.
c. Retighten the rocker arm pivot lock nut while holding
the rocker arm pivot.
d. Recheck valve clearance after tightening the rocker
arm pivot lock nut.
5. Apply liquid gasket (Hondabond 4, Three Bond 1207, or
equivalent) to the cylinder head cover installation surface,
and install the cylinder head cover.
ROCKER ARM
ROCKER ARM PIVOT
LOCK NUT
ROCKER ARM PIVOT
To increase valve clearance: screw out.
To decrease valve clearance: screw in.
Date of Issue: April 2008
3-7
WDP30X
8. IDLE SPEED
a. PILOT SCREW
THROTTLE STOP SCREW
The pilot screw is fitted with a limiter cap that prevents
excessive enrichment of the air-fuel mixture in order to
comply with emissions regulations.
Do not attempt to remove the limiter cap for pilot screw
adjustment. The limiter cap cannot be removed without
breaking the pilot screw.
b. THROTTLE STOP SCREW
With the engine at normal operating temperature, turn the
throttle stop screw to obtain the specified idle speed.
Standard idle speed
1,400 ± 150 rpm
FUEL VALVE
9. FUEL STRAINER CUP
 WARNING
Gasoline is highly flammable and explosive.
OFF
You can be burned or seriously injured when handling
fuel.
• Keep heat, sparks and flame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
O-RING
FUEL
STRAINER
CUP
K2
CLEANING
1. Turn off the fuel valve and remove the fuel strainer cup
and O-ring.
2. Wash the strainer cup in nonflammable or high flash point
solvent.
3. Install the O-ring and sediment cup. Tighten the sediment
cup to the specified torque.
TORQUE: 3.9 N•m (2.9 lb•ft)
Align
4. After cleaning and assembly, check for leaks. Be sure
there is no spilled fuel before starting the engine.
CUP FILTER
3-8
Date of Issue: April 2008
WDP30X
10. FUEL TANK & FUEL FILTER
 WARNING
Gasoline is highly flammable and explosive.
You can be burned or seriously injured when handling
fuel.
• Keep heat, sparks and flame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
CLEANING
1. Drain the fuel from the fuel tank into a suitable container.
2. Remove the fuel tank (P. 5-5).
3. Disconnect the fuel tube and unscrew the fuel filter from
the fuel tank.
4. Wash the fuel filter in nonflammable or high flashpoint
solvent. Inspect the fuel filter screen to be sure it is
undamaged.
5. Clean the fuel tank with nonflammable or high flashpoint
solvent and allow to dry thoroughly.
6. Check to be sure the O-ring is in place and install the
strainer and fuel valve. Tighten the fuel valve nut to the
specified torque.
TORQUE: 22 N•m (16 ft•lb)
7. After assembly, check for fuel leaks.
Date of Issue: April 2008
FUEL TANK
O-RING
FUEL FILTER
JOINT NUT
FUEL FILTER
FUEL TUBE
3-9
WDP30X
11. GOVERNOR
ADJUSTMENT
1. Remove the fuel tank.
2. Loosen the pinch bolt and nut, and then move the
governor arm so that the throttle is completely open.
3. Rotate the governor arm shaft as far as it will go in the
direction that it was just turned by the governor arm, and
retighten the pinch bolt and nut.
4. Reinstall the fuel tank.
5. Start the engine and warm it up fully, and bring the
engine to its standard speed with the throttle lever.
Adjust the throttle control screw so that the throttle
cannot be moved past this point.
Maximum speed
THROTTLE CONTROL SCREW
PINCH
BOLT/NUT
GOVERNOR ARM
GOVERNOR ARM SHAFT
3,000 ~ 3,150 rpm
12. PUMP CLAPPET VALVE
CLAPPET VALVE
INSPECTION
Inspect the clappet valves. If they are worn, torn, or
damaged, replace them. If the case sealing surface is
damaged or cannot be cleaned, an optional stainless steel
wear plate and paper gasket can be installed.
PAPER GASKET
(optional)
STAINLESS STEEL
WEAR PLATE (optional)
3-10
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
WDP30X
4. AIR CLEANER/CARBURETOR
1. AIR CLEANER . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
2. CARBURETOR . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
1. AIR CLEANER
REMOVAL/INSTALLATION
P. 3-4
P. 3-4
Date of Issue: April 2008
4-1
WDP30X
K2
NUT
AIR CLEANER COVER
INSTALLATION:
Install the air cleaner cover with the long
skirt portion facing toward the front.
WING NUT
INNER FILTER (PAPER)
BOLT (6 x 20 mm)
GROMMET
OUTER FILTER (FOAM)
COLLAR
AIR CLEANER
ELBOW SEAL
CARBURETOR SPACER
INSTALLATION:
Before installing, check for damage.
Note the installation direction.
BREATHER TUBE
AIR CLEANER ELBOW
REMOVAL/
INSTALLATION:
Remove and install the air
cleaner elbow with the fuel
valve lever in the OFF
position and the choke lever
in the CLOSE position.
Before installation, clean the
inside of the air cleaner
AIR CLEANER COLLAR (2)
Viewed from air cleaner side
4-2
AIR CLEANER ELBOW NUT (6 mm) (2)
9 N·m (0.9 kgf·m, 80 in·lb)
Date of Issue: April 2008
WDP30X
2. CARBURETOR
a. REMOVAL/INSTALLATION
THROTTLE
RETURN SPRING
GOVERNOR ROD
FUEL TUBE
ASSEMBLY:
SPARK PLUG
WIRE
INSULATOR
GASKET
CARBURETOR
GASKET
Date of Issue: April 2008
4-3
WDP30X
b. DISASSEMBLY/ASSEMBLY
CLEANING: P.
P. 4-5
4-5
REPLACEMENT:P.P.4-4
4-4
REPLACEMENT: P.
P. 4-5
4-5
ASSEMBLY:
ASSEMBLY:
CLEANING: P.
P. 3-8
3-8
ASSEMBLY:
ASSEMBLY:
#60
ASSEMBLY:
4-4
Date of Issue: April 2008
WDP30X
c. INSPECTION
FLOAT LEVEL HEIGHT
FLOAT LEVEL GAUGE
07401-0010000
Place the carburetor in the position as shown and measure
the distance between the float top and carburetor body
when the float just contacts the seat without compressing
the valve spring.
Standard float height
13.7 mm (0.54 in)
If the height is outside the specification, replace the float and
recheck the float height.
d. REPLACEMENT
LIMITER CAP
PILOT SCREW
PILOT SCREW AND LIMITER CAP
Only remove the pilot screw and limiter cap when necessary
for repair or to clean stubborn deposits from the pilot circuit
passages.
Removal of the limiter cap requires breaking the pilot screw.
A new pilot screw and limiter cap must be installed.
Pilot screw breaks at narrow point.
NOTICE
Tampering is a violation of Federal and California law.
1. When the limiter cap has been broken off, remove the
broken pilot screw.
2. Place the spring on the replacement pilot screw, and
install it on the carburetor.
3. Turn the pilot screw in until it is lightly seated, then turn
the screw out the required number of turns.
Pilot screw opening
1-5/8 turns out
4. Apply LOCKTIGHT® 638 to the inside of the limiter cap,
then install the cap so its stop prevents the pilot screw
from being turned counterclockwise.
Be careful to avoid turning the pilot screw while installing
the limiter cap. The pilot screw must stay at its required
setting.
Revised:
April 2012
Date of Issue:
April (PSV61TDP00E2)
2008
PILOT SCREW
STOP
LIMITER CAP
4-5
WDP30X
e. CLEANING
 WARNING
To prevent serious eye injury, always wear safety
goggles or other eye protection when using
compressed air.
NOTICE
• Some commercially available chemical cleaners are very
caustic. These cleaners may damage plastic parts such as
O-rings, floats, and float seats. Check the container for
instructions. If you are in doubt, do not use these products to
clean Honda carburetors.
• High air pressure may damage the carburetor. Use low air
pressure (30 psi or less) when cleaning passages and ports.
1. Clean the carburetor body with high flash point solvent.
2. Use low air pressure and clean the following passages
and ports:
• Pilot screw hole
• Pilot jet hole
• Pilot air jet
• Main air jet
• Transition ports
• Pilot outlet
• Main nozzle holder
• Internal vent port
4-6
Date of Issue: April 2008
5. RECOIL STARTER/FUEL TANK
WDP30X
1. RECOIL STARTER . . . . . . . . . . . . . . . . . . . . . . 5-1
3. FUEL TANK . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
2. FAN COVER . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
1. RECOIL STARTER
a. REMOVAL/INSTALLATION
RECOIL STARTER ASSEMBLY
INSTALLATION:
Remove dirt and debris before
installation.
ASSEMBLY: P.
P. 5-2
5-2
6 x 10 (3)
FAN COVER
6 x 12 (4)
b. DISASSEMBLY
 WARNING
•
Wear gloves and eye protection.
•
During assembly, take care not to allow the return spring to come out.
COVER BOLT
WASHER
RATCHET (2)
STARTER REEL
RETURN SPRING
RATCHET COVER
STARTER
GRIP
FRICTION SPRING
RATCHET SPRING (2)
RECOIL STARTER ROPE
ASSEMBLY:
Check the rope for fraying or
wear before installation.
Date of Issue: April 2008
STARTER
CASE
5-1
WDP30X
c. ASSEMBLY
1. Insert the starter rope into the recoil starter reel and tie
the rope as shown.
2. Wind the rope onto the reel counterclockwise.
STARTER REEL
STARTER ROPE
3. Wind the spring and install it to the recoil starter reel by
aligning the outer end to the groove of the reel.
STARTER REEL
RETURN SPRING
4. Apply grease to the spring hook and boss of the starter
case. Align the spring inner hook to the case claw on
the case by turning the reel counterclockwise.
5. Apply grease to the friction spring and inside of the
ratchet cover.
6. Install the ratchet spring and ratchet as shown.
7. Install the friction spring, and then install the ratchet
cover by aligning the tip of the ratchet with the arrow
mark on the ratchet cover. Tighten the cover bolt
securely.
STARTER REEL
STARTER CASE
RATCHET COVER
FRICTION SPRING
RATCHET
SPRING
RATCHET
5-2
COVER
BOLT
ARROW
MARK
Date of Issue: April 2008
WDP30X
8. Turn the reel three full turns counterclockwise to preload
the return spring.
9. Pass the rope through the starter case hole and starter
grip, and knot the end of the rope as shown.
STARTER GRIP
CASE HOLE
10.Check the operation of the ratchet by pulling the starter
rope out several times.
Date of Issue: April 2008
5-3
WDP30X
2. FAN COVER
REMOVAL/INSTALLATION
From ignition coil
ENGINE
SWITCH
BLACK
OIL
ALERT
UNIT
YELLOW
YELLOW
Retaining clip
5-4
From oil level
switch
Date of Issue: April 2008
WDP30X
3. FUEL TANK
REMOVAL/INSTALLATION
FUEL TANK CAP
Gasoline is highly flammable and explosive.
You can be burned or seriously injured when handling
fuel.
• Keep heat, sparks and flame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
ASSEMBLY:
Make sure that the air vent hole is
clean and unclogged. Blow with
compressed air if necessary.
TANK CAP PACKING
Turn the fuel valve lever to the OFF position.
FUEL TANK
FUEL TANK CAPACITY:
2.6 (0.69 US gal)
P.3-9
3-9
CLEANING: P.
FUEL STRAINER
ASSEMBLY:
Make sure that the strainer is clean
and undamaged before installation.
FUEL FILTER
O-RING
TORQUE:
2 N·m (1.4 ft-lb)
CLEANING:P.P.3-9
3-9
PINCH BOLT
6 mm NUT
FUEL TUBE
INSPECTION:
Check for damage or leakage.
Replace if necessary.
TUBE CLIP
GOVERNOR ARM
ASSEMBLY:
Hook the governor spring on the
hole marked 1.
“1” MARK
THROTTLE RETURN SPRING
ASSEMBLY:
Install with the long end side
toward the control base.
6 x 12 (2)
GOVERNOR SPRING
CONTROL BASE
6 x 29
ASSEMBLY:
Install with the long end side
toward the control base.
6 mm FLANGE NUT (2)
10 N·m (7 ft-lb)
Date of Issue: April 2008
5-5
WDP30X
FUEL FILLER CAP
FUEL FILLER CAP PACKING
CHECK:
Check for deterioration or cracks.
K2
FUEL TANK
O-RING
FUEL TANK JOINT
2 N·m (0.2 kgf·m, 18 lin·lb)
CHECK:
Check the screen of the fuel tank
joint for clogs or damage.
FUEL TANK NUT (6 mm) (2)
10 N·m (1.0 kgf·m, 89 in·lb)
FUEL TANK BOLT (6 x 29 mm)
10 N·m (1.0 kgf·m, 7 lbf·ft)
FUEL TUBE
CHECK:
Check for deterioration or cracks.
FUEL FILLER CAP REMOVAL/INSTALLATION
Turn the fuel level gauge (1) to align the fuel filler cap tether hole (2)
with the cutout (3) of the fuel filler neck, and then remove the fuel
filler cap (4).
(5)
(4)
Before installing, check the air vent hole of the fuel filler cap for clogs.
If necessary, clean it using low-pressure compressed air.
Set the fuel tank cap to the fuel filler neck by aligning the projections
(5) of the cap with the cutouts of the fuel filler neck and fuel level
gauge, and then turn the fuel tank cap clockwise 180 degrees to lock
it.
(1)
(2)
(3)
5-6
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
6. MUFFLER
WDP30X
1. MUFFLER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
1. MUFFLER
DISASSEMBLY/ASSEMBLY
 CAUTION
The engine and muffler become very hot during
operation, and they remain hot for a while after
operation. Be sure that the engine is cold before
muffler removal/installation.
UPPER MUFFLER PROTECTOR
5 x 8 mm SELF-TAPPING SCREW (4)
MUFFLER
ASSEMBLY:
Install the muffler after removing
the carbon deposits with a plastic
hammer.
4 x 6 mm
SELF-TAPPING SCREW
SPARK ARRESTER
(optional)
CLEANING: P.
P.3-6
3-6
8 mm HEX NUT (2)
24 N·m (17 ft-lb)
MUFFLER GASKET
Do not reuse.
Date of Issue: April 2008
6-1
WDP30X
6-2
Date of Issue: April 2008
7. FLYWHEEL/IGNITION COIL
WDP30X
1. FLYWHEEL/IGNITION COIL . . . . . . . . . . . . . . . 7-1
1. FLYWHEEL/IGNITION COIL
a. DISASSEMBLY/ASSEMBLY
BLACK LEAD
WOODRUFF KEY
ASSEMBLY:
Insert securely into the two
ribs on the crankcase as
shown.
ASSEMBLY:
After installing the flywheel,
check to be sure that the
woodruff key is still in its
slot on the crankshaft.
FLYWHEEL
DISASSEMBLY:
• Remove the ignition coil before removing
the flywheel.
• Do not hit the flywheel with a hammer.
Remove with a commercially available
6-inch puller. Avoid the magnet section
when attaching the puller.
SIDE PLATE
FLYWHEEL PULLER
(Commercially available)
6 x 20
ASSEMBLY:
Clean the crankshaft tapered surface
before installation.
14 mm SPECIAL NUT
75 N·m (7.5 kgf·m, 54 lbf·ft)
6 x 25 (2)
IGNITION COIL
ADJUSTMENT:P.
P.7-2
7-2
INSPECTION: P.
P.7-2
7-2
HIGH TENSION CORD
ASSEMBLY:
Check for cracked or damaged insulation
and replace if necessary.
STARTER PULLEY
DISASSEMBLY:
Attach by aligning the lug (A) on the
pulley with the small hole (B) at the
center of the flywheel.
(B)
(A)
COOLING FAN
DISASSEMBLY/ASSEMBLY:
When disassembling and assembling,
take care not to damage the fan blade.
Attach by aligning the four lugs on
the rear side of the fan with the
small holes in the flywheel.
Date of Issue: April 2008
7-1
WDP30X
b. ADJUSTMENT
IGNITION COIL
Adjustment is required only when the ignition coil or the
flywheel has been removed.
1. Loosen the ignition coil bolt.
2. Insert the feeler gauge between the ignition coil and
flywheel.
3. Push the ignition coil firmly against the flywheel and
tighten the ignition coil bolt. Remove the feeler gauge.
Specified clearance
0.2 ~ 0.6 mm
(0.008 ~ 0.024 in
IGNITION COIL
FLYWHEEL
0.2~0.6 mm
(0.008 ~ 0.024 in)
c. INSPECTION
IGNITION COIL
<Primary side>
Measure the resistance of the primary coil by attaching
one ohmmeter lead to the ignition coil’s primary (black)
lead while touching the other lead to the iron core.
Primary side resistance
0.8 ~ 1.0 
<Secondary side>
Remove the spark plug cap. Measure the resistance of the
secondary side of the coil by attaching one ohmmeter lead
to the ignition coil terminal and the other lead at the spark
plug cap end.
Secondary side resistance
7-2
5.9 ~ 7.1 k
Date of Issue: April 2008
WDP30X
SPARK PLUG CAP
Measure the resistance of the spark plug cap by touching
one test lead at the wire end of the cap, and the other at the
spark plug end.
Resistance
7.5 ~ 12.5 k
SPARK PLUG CAP
Date of Issue: April 2008
7-3
WDP30X
7-4
Date of Issue: April 2008
8. CYLINDER HEAD/VALVES
WDP30X
1. CYLINDER HEAD/VALVES . . . . . . . . . . . . . . . . 8-1
1. CYLINDER HEAD/VALVES
a. REMOVAL/INSTALLATION
8 x 55 (4)
TORQUE:
24 N•m (18 ft-lb)
REMOVAL/INSTALLATION:
Loosen and tighten the bolts in a
crisscross pattern in 2 ~ 3 steps.
SPARK PLUG
ADJUSTMENT: P.
P. 3-5
3-5
CYLINDER HEAD
GASKET
CYLINDER BLOCK
CYLINDER HEAD
COVER GASKET
6 x 12 (4)
CYLINDER
HEAD COVER
DOWEL PIN (2)
6 x 12 (2)
CYLINDER HEAD
SHROUD
Date of Issue: April 2008
REMOVAL/INSTALLATION:
• Before installation, remove any
carbon deposits from the combustion chamber and inspect
the valve seats.
• Measure the cylinder compression after assembly.
DISASSEMBLY/ASSEMBLY:
P. 8-2
8-2
8-1
WDP30X
b. DISASSEMBLY/ASSEMBLY
VALVE SPRING RETAINER (2)
DISASSEMBLY:
Push down and slide the retainer to the
side, so the valve stem slips through the
hole at the side of the retainer.
ASSEMBLY:
The exhaust valve retainer has a larger
center recess than the intake valve retainer,
so it can accept the valve rotator.
EXHAUST VALVE
VALVE GUIDE (2)
REPLACEMENT:P.
P.8-5
8-5
Do not remove the valve spring retainers
while the cylinder head is installed, or the
valves will drop into the cylinder.
VALVE STEM SEAL
(Intake valve only)
ASSEMBLY:
Before installation, remove
carbon deposits and inspect
the valve.
Do not interchange with the
intake valve.
INSPECTION: P.
P. 8-4
8-4
VALVE HEAD DIAMETER:
19 mm (0.75 in)
CLIP
(EX side only)
VALVE ROTATOR
(Exhaust valve only)
ASSEMBLY:
If the valve rotator is not
installed, the exhaust valve
may drop into the cylinder
when starting the engine.
VALVE SPRING (2)
INSPECTION:
P.
P. 8-3
8-3
ROCKER ARM
PIVOT (2)
INTAKE VALVE
ASSEMBLY:
Do not interchange with
the exhaust valve.
8-4
INSPECTION: P. 8-4
VALVE HEAD DIAMETER:
22 mm (0.87 in)
ROCKER ARM PIVOT
LOCK NUT (2)
10 N•m (7 ft-lb)
PUSH ROD GUIDE
CYLINDER HEAD
INSPECTION: P.
P. 8-3
8-3
ROCKER ARM (2)
ASSEMBLY:
Before installing, check
for wear on the surfaces
that contact the pivot
bolt, push rod, and rocker
arm pivot.
8-2
PUSH ROD (2)
ROCKER ARM
PIVOT STUD (2)
24 N•m (17 ft-lb)
ASSEMBLY:
Check both ends for wear, and
check the rod for straightness.
Be sure the rod ends are firmly
seated in the lifters.
Date of Issue: April 2008
WDP30X
c. INSPECTION
• VALVE SPRING FREE LENGTH
Measure the free length of the valve springs.
Standard
Service limit
30.5 mm (1.20 in)
29.5 mm (1.16 in)
Replace the springs if they are shorter than the service limit.
• VALVE SEAT WIDTH
Measure the valve seat width.
Standard
Service limit
0.8 mm (0.03 in)
2.0 mm (0.08 in)
If the valve seat width is under the standard, or over the
service limit, recondition the valve seat (P. 8-6).
• CYLINDER HEAD
FEELER GAUGE
STRAIGHTEDGE
Remove carbon deposits from the combustion chamber.
Clear any gasket material from the cylinder head surface.
Check the spark plug hole and valve areas for cracks. Check
the cylinder head for warpage with a straightedge and a
feeler gauge.
Service limit
Date of Issue: April 2008
0.10 mm (0.004 in)
8-3
WDP30X
• VALVE STEM O.D.
Inspect each valve for face irregularities, bending, or
abnormal stem wear. Replace the valve if necessary.
Measure and record each valve stem O.D.
Standard
Service limit
IN
5.48 mm (0.216 in)
5.318 mm (0.2094 in)
EX
5.45 mm (0.215 in)
5.275 mm (0.2077 in)
Replace the valves if their O.D. is smaller than the service
limit.
• VALVE GUIDE I.D.
Ream the valve guides to remove any carbon deposits
before measuring.
Measure and record each valve guide I.D.
Standard
Service limit
5.50 mm (0.217 in)
5.572 mm (0.2194 in)
VALVE GUIDE
REAMER, 5.5 mm
07984-200000D
Replace the guides if they are over the service limit (P. 8-5).
• GUIDE-TO-STEM CLEARANCE
Subtract each valve stem O.D. from the corresponding guide
I.D. to obtain the guide-to-stem clearance.
Standard
Service limit
IN
0.020 ~ 0.044 mm
(0.0008 ~ 0.0017 in)
0.10 mm (0.004 in)
EX
0.050 ~ 0.077 mm
(0.0019 ~ 0.0030 in)
0.12 mm (0.005 in)
If the guide-to-stem clearance exceeds the service limit,
determine if the new guide with standard dimensions would
bring the clearance within tolerance. If so, replace any guide
as necessary and ream to fit. If the guide-to-stem clearance
exceeds the service limit with new guides, replace the valves
as well.
Recondition the valve seats whenever the valve guides are
replaced (P. 8-6).
8-4
Date of Issue: April 2008
WDP30X
d. VALVE GUIDE REPLACEMENT
1. Chill the replacement valve guides in the freezer section
of a refrigerator for about an hour.
2. Use a hot plate or oven to heat the cylinder head evenly
to 150°C (300°F).
 CAUTION
To avoid burns, use heavy gloves when handling the
heated cylinder head.
NOTICE
• Do not use a torch to heat the cylinder head; warpage of
the cylinder head may result.
• Do not get the head hotter than 150°C (300°F);
excessive heat may loosen the valve seats.
3. Remove the heated cylinder head from the hot plate and
support it with wooden blocks. Drive the valve guides out
of the head from the combustion chamber side.
NOTICE
When driving the valve guides out, be careful not to
damage the head.
VALVE GUIDE
DRIVER, 5.5 mm
07942-8920000
4. Remove the new valve guides from the refrigerator one at
a time as needed.
5. Install the new valve guides from the valve spring side of
the cylinder head.
Exhaust side: Drive the exhaust valve guide until the clip
is fully seated as shown.
Intake side: Drive the intake valve guide to the specified
height (measured from the top of the valve
guide to cylinder casting as shown).
IN valve installation height
EXHAUST:
CLIP
VALVE GUIDE
DRIVER, 5.5 mm
07942-8920000
INTAKE:
3.0 mm (0.36 in)
3.0 mm (0.12 in)
6. After installation, inspect the valve guide for damage.
Replace the guide if damaged.
Date of Issue: April 2008
8-5
WDP30X
• VALVE GUIDE REAMING
For best results, be sure the cylinder head is at room
temperature before reaming valve guides.
1. Coat the reamer and valve guide with cutting oil.
2. Rotate the reamer clockwise through the valve guide the full
length of the reamer.
VALVE GUIDE
REAMER, 5.5 mm
07984-200000D
3. Continue to rotate the reamer clockwise while removing it
from the valve guide.
4. Thoroughly clean the cylinder head to remove any cutting
residue.
5. Check the valve guide bore; it should be straight, round,
and centered in the valve guide. Insert the valve and check
operation. If the valve does not operate smoothly, the guide
may have been bent during installation. Replace the valve
guide if it is bent or damaged.
6. Check the valve guide-to-stem clearance (P. 8-4).
e. VALVE SEAT RECONDITIONING
1. Thoroughly clean the combustion chamber and valve seats
to remove carbon deposits.
Apply a light coat of Prussian Blue or erasable felt-tipped
marker ink to the valve face.
2. Insert the valve, and snap it closed against its seat several
times. Be sure the valve does not rotate on the seat. The
transferred marking compound will show any area of the
seat that is not concentric.
Follow the instructions of the valve seat cutter
manufacturer.
3. Using a 45° cutter, remove enough material to produce a
smooth and concentric seat.
Turn the cutter clockwise, never counterclockwise.
Continue to turn the cutter as you lift it from the valve seat.
4. Use the 31° and 60° cutters to narrow and adjust the valve
seat so that it contacts the middle of the valve face. The 31°
cutter removes material from the top edge (contact too
high).
The 60° cutter removes material from the bottom edge
(contact too low). Be sure that the width of the finished
valve seat is within specification.
8-6
CONTACT TOO HIGH
31°
CONTACT TOO LOW
60°
Date of Issue: April 2008
WDP30X
Standard
Service limit
0.8 mm (0.03 in)
2.0 mm (0.08 in)
5. Make a light pass with 45° cutter to remove any possible
burrs at the edge of the seat.
m
m in)
8
0. .03
(0
6. After resurfacing the seats, inspect for even valve
seating. Apply Prussian Blue compound or erasable felttipped marker ink to the valve faces. Insert the valve, and
snap it closed against its seat several times. Be sure the
valve does not rotate on the seat.
The seating surface, as shown by the transferred
marking compound, should have good contact all the way
around.
7. Lap the valves into their seats, using a hand valve lapper
and lapping compound (commercially available).
NOTICE
To avoid severe engine damage, be sure to remove all
lapping compound from the engine before assembly.
Adjust the valve clearance after assembly (P. 3-7).
Date of Issue: April 2008
8-7
WDP30X
8-8
Date of Issue: April 2008
9. CRANKCASE COVER/CRANKSHAFT/PISTON
WDP30X
1. CRANKCASE COVER/CRANKSHAFT . . . . . . . 9-1
2. GOVERNOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-8
1. CRANKCASE COVER/CRANKSHAFT
a. DISASSEMBLY/ASSEMBLY
CAMSHAFT
PISTON
ASSEMBLY:
Install with the triangle mark
toward the push rod hole.
DISASSEMBLY/
ASSEMBLY: P.
P.9-3
9-2
INSPECTION: P.
P.9-4
9-4
TRIANGLE MARK
PUSH ROD HOLE
22 x 35 x 6 mm
OIL SEAL
CYLINDER BLOCK
ASSEMBLY:
Before installing, inspect
for worn and weakened
springs and check that
the decompressor weight
moves smoothly.
INSPECTION: P.
P. 9-7
9-7
DECOMPRESSOR
WEIGHT
VALVE LIFTER (2)
DISASSEMBLY:
When removing, mark so that the IN and
EX sides can be distinguished.
ASSEMBLY:
Install the lifters immediately before
installing the camshaft.
CRANKSHAFT BEARING
62/22 (2)
INSPECTION: P.
P.9-8
9-8
P.
ASSEMBLY: P.9-2
9-2
CRANKCASE GASKET
CRANKCASE COVER
OIL FILLER CAP
10.2 mm
WASHER (2)
CORD CLIP
STAY
OIL DRAIN BOLT (2)
18 N·m (13 ft-lb)
DOWEL PIN (2)
CONNECTING ROD BOLT (2)
OIL SEAL
22 x 41 x 6 mm
12 N·m (9 ft-lb)
CONNECTING ROD CAP
CRANKSHAFT
ASSEMBLY:
Push in until the bearing touches the crankcase.
Be careful not to damage the oil seal.
INSPECTION: P.
P.9-7
9-6, 9-7
Date of Issue: April 2008
6 x 28 (7)
OIL FILLER CAP/
DIPSTICK
12 N·m (9 ft-lb)
OIL FILLER CAP PACKING (2)
9-1
WDP30X
• CRANKSHAFT BEARING
ASSEMBLY:
Oil the circumference of the bearing, and install the bearing
with the following special tools.
Driver
07749-0010000
Attachment, 52 x 55 mm
07746-0010400
Pilot, 22 mm
07746-0040100
• TIMING GEAR/GOVERNOR DRIVE GEAR
DISASSEMBLY:
Mark a line on the crankshaft and timing gear.
Set a commercially available bearing puller plate on the
bottom part of the governor drive gear, and remove the
crankshaft and timing gear using a hydraulic press.
Remove the governor drive gear in the same way.
ASSEMBLY:
• TIMING GEAR
Using the old gear for reference, make a mark at the same
position on the new gear.
Using a hydraulic press, driver, and attachment (special
tools), press the new gear onto the crankshaft.
Driver, 40 mm I.D.
07746-0030100
Attachment, 25 mm I.D.
07746-0030200
• GOVERNOR DRIVE GEAR
Use a hydraulic press and the special tools shown below to
press in a new governor drive gear.
Driver, 40 mm I.D.
07746-0030100
Attachment, 30 mm I.D.
07746-0030300
9-2
Date of Issue: April 2008
WDP30X
• PISTON
PISTON RINGS
ASSEMBLY:
• Install all rings with the markings facing up.
• Be sure that the top and second rings are not interchanged.
• Check that rings rotate smoothly after installation.
• Space the piston ring end gaps 120 degrees apart, and do not
align any gap with the piston pin bore.
TOP RING
(CHROME PLATED)
SECOND RING
OIL RING
(COMBINATION RING)
MARKING
INSPECTION: P. 9-4
120°
TOP RING
120°
120°
SECOND RING
10 mm (0.4 in)
SIDE RAIL (2)
OIL RING
SPACER
10 mm (0.4 in)
PISTON
PISTON PIN
PISTON PIN CLIP (2)
ASSEMBLY:
• Install by setting one end of
the clip in the piston groove,
holding the other end with
long needle- nose pliers, and
rotating the clip in.
• Do not align the end gap of
the clip with the cutout in
the piston pin bore.
PISTON
PIN CLIP
CONNECTING ROD
ASSEMBLY:
Install the connecting rod with
the long end toward the trianglemarked side of the piston.
INSPECTION: P.
P.9-5
9-5
Date of Issue: April 2008
CUT OUT
9-3
WDP30X
b. INSPECTION
• CYLINDER I.D.
Measure and record the cylinder I.D. at three levels in both
the “X” axis (perpendicular to crankshaft) and the “Y” axis
(parallel to crankshaft). Take the maximum reading to
determine cylinder wear and taper.
Standard
Service limit
60.0 mm (2.36 in)
60.165 mm (2.3687 in)
• PISTON SKIRT O.D.
Measure and record the piston O.D. at a point 10 mm (0.4 in)
from the bottom of the skirt and 90° to the piston pin bore.
Standard
Service limit
59.985 mm (2.3616 in)
59.845 mm (2.3561 in)
• PISTON -TO-CYLINDER CLEARANCE
Standard
Service limit
0.015 ~ 0.050 mm
(0.0006 ~ 0.0020 in)
0.12 mm (0.005 in)
10 mm (0.39 in)
• PISTON RING WIDTH
K1QX2
Standard
Service limit
Top/
Second
1.5 mm (0.059 in)
1.37 mm (0.054 in)
Oil
2.5 mm (0.098 in)
2.37 mm (0.093 in)
UT1(2)QX2
Standard
Service limit
Top
0.95 ~ 0.97 mm
(0.037 ~ 0.038 in)
0.93 mm (0.037
in)
Second
0.94 ~ 0.96 mm
(0.037 ~ 0.038 in)
0.92 mm (0.036
in)
• PISTON RING SIDE CLEARANCE
K1QX2
Standard
Service limit
Top/
Second/Oil
0.015 ~ 0.045 mm
(0.0006 ~ 0.0019 in)
0.15 mm
(0.006 in)
UT1(2)QX2
Standard
Service limit
Top
0.035 ~ 0.070 mm
(0.0014 ~ 0.0028 in)
0.150 mm
(0.0059 in)
Second
0.045 ~ 0.080 mm
(0.0018 ~ 0.0031 in)
0.150 mm
(0.0059 in)
9-4
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
WDP30X
• PISTON RING END GAP
K1QX2
Standard
Service limit
Top
Second
0.2 ~ 0.4 mm
(0.008 ~ 0.016 in)
1.0 mm (0.04 in)
Oil
0.15 ~ 0.35 mm
(0.008 ~ 0.014 in)
1.0 mm (0.04 in)
UT1(2)QX2
Standard
Service limit
Top
0.20 ~ 0.35 mm
(0.008 ~ 0.014 in)
1.0 mm (0.04 in)
Second
0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)
1.0 mm (0.04 in)
Oil
0.20 ~ 0.70 mm
(0.008 ~ 0.028 in)
1.0 mm (0.04 in)
PISTON RING
Use the top of the piston to position the ring horizontally in the
cylinder.
• PISTON PIN O.D.
Standard
Service limit
13.00 mm (0.51 in)
12.954 mm (0.5100 in)
• PISTON PIN BORE I.D.
Standard
Service limit
13.002 mm (0.5119 in)
13.048 mm (0.5137 in)
• PISTON-TO-PISTON PIN BORE CLEARANCE
Standard
Service limit
0.002 ~ 0.014 mm
(0.0001 ~ 0.0006 in)
0.08 mm (0.003 in)
• CONNECTING ROD SMALL END I.D.
Standard
Service limit
13.005 mm (0.5120 in)
13.07 mm (0.515 in)
Revised:
April 2012
Date of Issue:
April (PSV61TDP00E2)
2008
9-5
WDP30X
• CONNECTING ROD BIG END I.D.
Original size - Standard
Service limit
26.02 mm (1.024 in)
26.066 mm (1.0262 in)
Undersize - Standard
Service limit
25.770 ~ 25.783 mm
(1.0146 ~ 1.0151 in)
25.816 mm (1.0164 in)
• CRANKPIN O.D.
Standard
Service limit
25.98 mm (1.023 in)
25.92 mm (1.020 in)
• CONNECTING ROD BIG END SIDE CLEARANCE
Standard
Service limit
0.1 ~ 0.7 mm
(0.004 ~ 0.028 in)
1.1 mm (0.043 in)
• CONNECTING ROD BIG END OIL CLEARANCE
1. Clean all oil from the crankpin and connecting rod big end
surfaces.
CONNECTING
ROD BOLTS (2)
2. Place a piece of plastigauge on the crankpin, install the
connecting rod and cap, and tighten the connecting rod bolts
to the specified torque.
TORQUE: 12•m (1.2 kg•m, 9 ft•lb)
Do not rotate the crankshaft while the plastigauge is in place.
9-6
Date of Issue: April 2008
WDP30X
3. Remove the connecting rod and measure the plastigauge.
PLASTIGAUGE
Standard
Service limit
0.040 ~ 0.063 mm
0.0016 ~ 0.0025 in)
0.12 mm (0.005 in)
4. If the clearance exceeds the service limit, replace the
connecting rod and recheck the clearance.
PLASTIGAUGE SCALE
• CAMSHAFT CAM HEIGHT
Standard
Service limit
IN
27.70 mm (1.090 in)
27.45 mm (1.081 in)
EX
27.75 mm (1.093 in)
27.50 mm (1.083 in)
• CAMSHAFT O.D.
Standard
Service limit
13.984 mm (0.5506 in)
13.916 mm (0.5479 in)
• CAMSHAFT HOLDER I.D.
Standard
Service limit
14.0 mm (0.55 in)
14.048 mm (0.5531 in)
Date of Issue: April 2008
9-7
WDP30X
• CRANKSHAFT BALL BEARING FREE PLAY
PLAY
1. Clean the bearing in solvent and dry it.
2. Spin the bearing by hand and check for play. Replace the
bearing if it is noisy or has excessive play.
PLAY
AXIAL
RADIAL
2. GOVERNOR
LOCK PIN
DISASSEMBLY/ASSEMBLY
ASSEMBLY:
• Install the lock pin immediately after
installing the governor arm shaft, and
move the shaft over against the governor
slider.
• The lock pin must be installed with the
straight side of the pin against the
groove in the shaft.
GOVERNOR WEIGHT (2)
ASSEMBLY:
Check that the weights move freely.
GOVERNOR WEIGHT PIN (2)
CLIP (2)
GOVERNOR WEIGHT HOLDER
ASSEMBLY:
• Before installation, check for
wear and damage of the gear.
• Be sure to install the governor
weight before installing the
crankshaft.
ASSEMBLY:
Install firmly into the shaft groove.
6 mm PLAIN WASHER
ASSEMBLY:
Install inside the case.
6 mm PLAIN WASHER
GOVERNOR ARM SHAFT
GOVERNOR SLIDER
ASSEMBLY:
Spread the governor weights to install the
slider; then check to be sure the slider
moves smoothly.
6 mm
THRUST WASHER
9-8
Date of Issue: April 2008
10. CASE/DIAPHRAGM
WDP30X
1. CASE/DIAPHRAGM. . . . . . . . . . . . . . . . . . . . . 10-1
1. CASE/DIAPHRAGM
a. DISASSEMBLY/ASSEMBLY
12 x 1.75 x 50 mm HEX BOLT (4)
UPPER CASE
To GEARBOX
P. 11-1
12 mm FLAT WASHER (4)
12 mm FLAT WASHER (4)
12 x 1.75 x 40 HEX BOLT (4)
CRANK
NYLON WASHER (2)
LOCK WASHER
BUSHING COVER
HEX BOLT
10 mm LOCK WASHER
CRANK BEARING
10 x 1.5 x 20 HEX BOLT
54 N•m (40 lb·ft)
CONNECTING ROD
ASSEMBLY: P. 10-2
AIR CHAMBER
PLUG
12 x 1.75 NUT (4)
ASSEMBLY:
Apply Hondalock to
stud threads. Tighten
1/8 to 1/4 turn in an X
pattern until final
torque is achieved.
TORQUE:
47 N•m (35 lb·ft)
12 x 1.75 mm NUT (4)
47 N•m (35 lb·ft)
DIAPHRAGM
INSPECTION: P. 10-3
INSTALLATION: P. 10-3
12 mm FLAT
WASHER (4)
CONNECTING
ROD FLANGE
12 x 1.75-70 STUD (4)
Apply Hondalock to
threads.
PLUG O-RING
AIR CHAMBER
12 mm FLAT
WASHER (4)
FLANGE STUD (4)
Apply Hondalock to threads.
LOWER CASE
3 in DISCHARGE PORT
PUMP CASE
MOUNTING STUD (4)
3 in NIPPLE (2)
ASSEMBLY:
Apply pipe thread
sealant to threads.
To FRAME ASSEMBLY
P. 12-1
12 mm FLAT
WASHER (4)
12 x 1.75 mm NUT (4)
ASSEMBLY:
Apply Hondalock to stud threads.
TORQUE:
27 N•m (20 lb·ft)
Revised:
April 2012
(PSV61TDP00E2)
Date of Issue:
April 2008
STAINLESS STEEL WEAR PLATE
and PAPER GASKET (2) (optional)
Install if clappet valve sealing surfaces
are damaged, worn, or not sealing
properly.
3 in SUCTION PORT
CLAPPET VALVE (2)
ASSEMBLY:
• Discharge side valve is installed
with the flat side facing the case.
• Suction side valve is installed with
the flat side facing the port.
10-1
WDP30X

b. CONNECTING ROD
DISASSEMBLY
GREASE NIPPLE
1. Remove the roll pin and place the upper rod end
lightly in a vise.
2. Remove the bolt securing the spring and lower rod
end assembly.
UPPER ROD
END
ROLL PIN
SPRING
INNER RING
LOWER ROD
END
BOLT
ASSEMBLY
1. Place the upper rod end in a vise using slight
pressure.
2. Apply Hondalock to the threads of the bolt, and pass
the bolt through the lower rod end, inner ring, and
spring.
3. Tighten the bolt to compress the spring until the
assembly has an overall height of 300 mm (11.8 in).
4. Align the roll pin holes and install the roll pin.
10-2
300 mm
(11.8 in)
Date of Issue: April 2008
WDP30X
c. DIAPHRAGM
CONNECTING ROD
INSPECTION
Inspect the diaphragm for cracks, tears, or damage and
replace if necessary.
INSTALLATION
1. Install the connecting rod hex bolt with lock washer,
bushing cover, and nylon washer into the crank arm.
TORQUE: 54 N•m (40 lb•ft)
NYLON WASHER
BUSHING
COVER
10 mm LOCK
WASHER
CRANK ARM
10 x 1.5 x 20 HEX BOLT
54 N•m (40 lb·ft)
2. Pull the starter grip slowly until the diaphragm pulls up
against the upper case stops.
3. Install the upper case assembly, making sure the
diaphragm is centered and not pinched between the
case stops.
UPPER CASE
UPPER CASE STOP (4)
DIAPHRAGM
4. Tighten the case nuts in an X pattern 1/8 to 1/4 turn
until the final torque is achieved.
TORQUE: 47 N•m (35 lb•ft)
Date of Issue: April 2008
1
3
4
2
10-3
WDP30X
10-4
Date of Issue: April 2008
11. GEARBOX
WDP30X
1. GEARBOX . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-1
1. GEARBOX
SERVICE BULLETIN #7
DISASSEMBLY/ASSEMBLY
WDP30X up to S/N WZCA-6099999
KEY
KEY (3)
GEAR
SHAFT
WASHER
Continued
on next page
BEARING
GEARBOX CASE
VALVE
S/N WZCA-6000001
~ 6000824
GEAR
SHAFT
WASHER
BEARING
PLUG
S/N WZCA-6000001 ~ 6000824
SEAL
CAP/DIPSTICK
S/N WZCA-6000825 ~ later
PLUG
GASKET
PLUG
WASHER
To CASE/DIAPHRAGM
P.
P. 10-1
10-1
Revised:
April 2012
Date of Issue:
April (PSV61TDP00E2)
2008
11-1
WDP30X
WDP30X up to S/N WZCA-6099999
5/16 x 18 x 1.5
HEX BOLT (4)
ENGINE MOUNTING
BRACKET
5/16 in
WASHER (8)
6 x 1 x 25 mm
ALLEN SCREW (10)
LIFTING BAIL
PLUGS
PIN
GASKET
BEARING
10 x 1.5
STUD (4)
5/16 in
LOCKNUT (4)
15 N•m (11 ft-lb)
CLIP
ENGINE
ADAPTER
From
previous page
48-80-10M SEAL
PIN
COVER
BEARING
SHIM
11-2
NYLON WASHER (2)
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
WDP30X
WDP30XK1, K2 S/N WZCA-6200001 ~ later
KEY
GEAR (HELICAL)
SHAFT
KEY (3)
Continued
on next page
BEARING
GEARBOX CASE
GEAR (HELICAL)
SHAFT
WASHER
BEARING
CAP/DIPSTICK
SEAL
PLUG
GASKET
PLUG
WASHER
To CASE/DIAPHRAGM
P.
P. 10-1
10-1
Revised:
April 2012
Date of Issue:
April (PSV61TDP00E2)
2008
11-3
WDP30X
WDP30XK1, K2 S/N WZCA-6200001 ~ later
ENGINE MOUNTING
BRACKET
6 x 1 x 25 mm
ALLEN SCREW (10)
LIFTING BAIL
5/16 x 18 x 1.5
HEX BOLT (4)
5/16 in
WASHER (8)
PLUG (2)
PIN
PINION
GASKET
BEARING
5/16 in
LOCKNUT (4)
ENGINE
ADAPTER 15 N•m (11 ft-lb)
CLIP
48-80-10M SEAL
HELICAL PINION BEARING
From
previous page
PIN
BEARING
SHIM
11-4
SCREW
(8)
COVER
NYLON WASHER (2)
Revised: AprilDate
2012of(PSV61TDP00E2)
Issue: April 2008
12. FRAME/WHEELS
WDP30X
1. FRAME/WHEELS. . . . . . . . . . . . . . . . . . . . . . . 12-1
1. FRAME/WHEELS
DISASSEMBLY/ASSEMBLY
WDP30X S/N WZCA-6000001 ~ 6099999
To CASE/DIAPHRAGM
10-1
P.P.10-1
FRAME ASSEMBLY
12 mm FLAT WASHER (4)
FRAME SPRING (2)
12 mm STAR WASHER (4)
12 mm NUT (4)
Date of Issue: April 2012
12-1
WDP30X
WDP30XK1, K2 S/N WZCA-6100001 ~ later
5/16-18 x 1.5 in HEX BOLT (4)
5/16-18 NYLOCK NUT (4)
15 N•m (11 ft-lb)
AXLE SHAFT
Grease both ends.

FRAME ASSEMBLY
WHEEL (2)
QUICK RELEASE RING-PIN
20 mm PLAIN
WASHER (4)
HANDLE
SPLIT PIN (2)
3/8 x 1 3/4 in BOLT (2)
To CASE/DIAPHRAGM
P. 10-1
3/8 in WASHER (4)
FRAME SPRING
12 mm FLAT WASHER (4)
12 mm STAR WASHER (4)
3/8 - 16 LOCKNUT (2)
20 N•m (27 ft-lb)
12 mm NUT (4)
12-2
Date of Issue: April 2012
WDP30X
Air Cleaner
Cleaning ............................................................ 3-4
Installation/Removal .......................................... 4-1
Carburetor
Installation/Removal .......................................... 4-3
Disassembly ...................................................... 4-4
Cleaning ............................................................ 4-6
Clappet Valve......................................................... 3-10
Compression Test .................................................... 2-7
Crankshaft
Removal/Installation .......................................... 9-1
Runout Check.................................................... 9-4
Cylinder Head
Disassembly/Assembly...................................... 8-1
Inspection .......................................................... 8-3
Diaphragm ............................................................. 10-1
Dimensional Drawings ............................................. 1-4
Engine Oil
Change .............................................................. 3-2
Inspection .......................................................... 3-2
Engine Switch
Inspection .......................................................... 5-4
Installation ......................................................... 5-4
Fan Cover ................................................................ 5-4
Flywheel Disassembly/Assembly ............................. 7-1
Fuel Strainer ............................................................ 3-8
Fuel Tank
Draining and Cleaning ....................................... 3-9
Removal/Installation .......................................... 5-5
Fuel Tube
Inspection .......................................................... 5-5
Removal/Installation .......................................... 5-1
Gearbox
Assembly ......................................................... 11-1
Grease............................................................... 3-3
Governor
Adjustment....................................................... 3-10
Disassembly/Assembly...................................... 9-8
Idle Speed Adjustment ............................................. 3-8
Ignition Coil
Air Gap Adjustment ........................................... 7-2
Disassembly/Assembly...................................... 7-1
Inspection .......................................................... 7-2
Maintenance Schedule ............................................ 3-1
Maintenance Standards ........................................... 2-3
Muffler ...................................................................... 6-1
Performance Curve .................................................. 1-3
Piston
Connecting Rod................................................. 9-5
Disassembly/Assembly...................................... 9-1
Recoil Starter
Removal/Installation .......................................... 5-1
Starter Rope Replacement ................................ 5-2
Rocker Arm Inspection............................................. 8-2
Date of Issue: April 2008
13. INDEX
Safety Messages................................................ i
Serial Numbers Location ..........................................2-2
Service Rules ...........................................................2-1
Spark Arrester ..........................................................3-6
Spark Plug
Inspection...........................................................3-5
Testing ...............................................................2-8
Specifications
Dimensions, Weights, and Capacities ...............1-1
Engine ................................................................1-1
Maintenance ......................................................2-3
Service ...............................................................2-3
Symbols....................................................................2-1
Tools
Commercially Available......................................2-6
Special ...............................................................2-5
Torque Values ..........................................................2-4
Troubleshooting........................................................2-7
Valve
Clearance Adjustment........................................3-7
Disassembly/Assembly ......................................8-2
Wheels....................................................................12-1
Wiring Diagram.........................................................1-5
13-1
WDP30X
13-2
Date of Issue: April 2008