null  User manual
Section 7
FUEL SYSTEM
Page
Before You Begin Servicing ..............e...mmi.eseereerie roer ene eee. 7-3
Introduction ..................... eee eee eerenereereenerneaeeearererarerarearereneo. 7-4
Specifications ................e.erecenecernarone ear erre aereo ee. 7-4
Test and Adjustment Specifications .....................eeve2m a 7-4
Special Torque Specifications ................e.eeeeen0reeri evecare, 7-4
Special Service Tools ..................e..eeeeerrercii Renee near 7-5
Measuring Instruments ................_....e....veiei eee nece. 7-5
Fuel System Operation ................. eee aroneese anse rene en seen eee 7-6
Fuel Injection PUMP ocean 7-6
U enan 7-7
Fuel System Diagram... iver erase, 7-8
Fuel System Components ................eeerereiererneera DDD 7-9
Checking and Adjusting Fuel Injection Timing ................—.........— 7-10
Checking Fuel Injection Timing RER 7-10
Adjusting Fuel Injection Timing ............e....xexemmrrererer 7-13
Fuel Injection Pump ..............e. eee enero EEE RE 7-15
Removal of Fuel Injection Pump ..................... eee 7-15
Installation of Fuel Injection Pump... eee 7-16
Replacement and/or Adjustment of the Fuel Limiter ............... 7-17
Fuel INjJECtON .….…........…........rrcrrrerseresme esse ns esaan aa sens ane r ane cr ere 7-21
Removal of Fuel Injector .................eemeevereienie ener e eee 7-21
Testing of Fuel Injector ...............eceesvermnenii eee eee, 7-22
Disassembly and Inspection of Fuel Injector ....................—.—.... 7-23
Adjusting Fuel Injector Pressure ..................eme e 7-24
Reassembly of Fuel Injector ...................eeeeeei eee 7-25
Installation of the Fuel Injector ................. reves 7-25
Speed Control Device ouverte eee eee eevee aaa es 7-26
Variable Speed TYPE cocci eee eraser ena 7-27
Remote Control Type ...................e eee ener e. 7-28
Variable Speed Friction Plate Type ...................eomrrn ER 7-29
Constant Speed TYPE esse RER DA: 7-30
LV Service Manual
7-1
FUEL SYSTEM
This Page Intentionally Left Blank
- LV Service Manual LS
FUEL SYSTEM
BEFORE YOU BEGIN
SERVICING
Before performing any service procedures within
this section, read the following safety information
and review the Safety section on page 3-1.
ENTANGLEMENT HAZARD!
* ALWAYS stop the engine before you
begin to service it.
e NEVER leave the key in the key switch
when you are servicing the engine.
Someone may accidentally start the
engine and not realize you are
servicing it.
* Failure to comply could result in death
or serious injury.
0000010en
FUME / BURN HAZARD!
ALWAYS read and follow safety related
precautions found on containers of
hazardous substances like parts
cleaners, primers, sealants and
sealant removers.
* Failure to comply could result in death
or serious injury.
00000 14en
SUDDEN MOVEMENT HAZARD!
» ALWAYS allow the engine to warm-up
for at least 5 minutes to allow the
engine idle speed to return to normal
before engaging the transmission or
any PTO attachments.
* NEVER engage the transmission or
PTO at an elevated engine speed.
* Failure to comply could result in death
or serious injury.
0000006en
* NEVER remove or attempt to remove
the tamper-proof devices from the
high-speed throttle limit screw. This
adjustment has been made at the
factory to meet all applicable
emissions regulations and then
sealed.
* DO NOT attempt to remove or adjust
the fuel limiter assembly.
* NEVER attempt to make adjustments
to any sealed adjustment screw.
* Any alterations to this engine may
affect the warranty coverage of this
engine.
See Yanmar Limited Warranty in
Section 2.
0000174en
LV Service Manual
FUEL SYSTEM
INTRODUCTION
This section of the Service Manual describes the
procedures necessary to remove, install and time
the fuel injection pump, fuel injector and the
associated system components.
SPECIFICATIONS
Test and Adjustment Specifications
Fuel Injector Pressure Fuel Injection Timing
2843 psi See Checking and Adjusting Fuel Injection Timing on page 7-
(19.6 MPa, 200 kgf/cm?) 10.
Note: Each 0.004 in. (0.1 mm) change in shim thickness in the fuel injector will result in approximately a
284 psi (1.96 MPa, 20 kgf/cm?) pressure change. See Adjusting Fuel Injector Pressure on page 7-24.
Special Torque Specifications
Lubricating Oil
Thread Diameter an
Application
Component Model and Pitch Torque (Thread Portion
| and Seat Surface)
| 30 - 35 Ib-ft |
Fuel Nozzle Case Nut U-0.605-40UNS-2B (40.7 - 47.5 N.m, Not Applied
a 4.2 - 4.8 kgf-m)
Fuel Pump Deliver 21.5 - 25 Ib
Valve (if Е De i M14 x 15 mm (29.4 - 34.3 N-m, Not Applied
quipp 3.0 - 3.5 kfg-m)
Fuel Injection Pum 87 - 104 lo-in.
Nuts ump 3-M6 x 1.0 mm (9.8 - 11.8 N-m, Not Applied
1.0 - 1.2 kgf-m)
Fuel Injection Nozzle 61.3 - 79 lo-in.
Nuts All Models 2-M6 x 1.0 mm (6.9 - 8.9 N-m, Not Applied
0.7 - 0.9 kgf-m)
Fuel injection Pump 87 - 104 lb-in.
Inspection Window 3-M6x1.0 mm (9.8 - 11.8 N-m, Not Applied
Plate Nuts 1.0 - 1.2 kgf-m)
a 215-218 lb-in.
Fuel miter Mounting . | (242-246N-m, Not Applied
2.4 - 2.5 kgf-m)
CL 19.8 - 23.5 Ib-ft
Infection Lino Nuts - (26.9 - 31.9 N-M, Not Applied
2.7 - 3.3 kaf-m)
See Tightening Torques for Standard Boits and Nuts on page 4-20, for standard hardware torque values.
7-4 | LV Service Manual
FUEL SYSTEM
SPECIAL SERVICE TOOLS
No. Tool Name Application Illustration
For tightening nuts and bolts to the specified
torque gE m
0000840
1 Torque Wrench (Available Locally)
MEASURING INSTRUMENTS
No. Instrument Name Application Illustration
For observing injection spray pattern of fuel
1 Fuel Injector Tester (Available Locally) injection nozzle and measuring injection
| pressure
5 Fuel Adjustment Jig Used to adjust fuel injection timing and fuel AN
(Yanmar P/N 114771-92310) limiter. |
3 Spill-Timing Tool* | Locally Fabricated Used to set fuel injection timing
*
Make from a short piece of the end of a high-pressure fuel injection line, a high-pressure fuel injection line nut, anda
short piece of clear plastic tubing (a thin nozzle from an aerosol spray can works well). Drill out the end of the fuel line to
accept the nozzle. Use a small amount of silicone sealant to seal the nozzle into the fuel line.
LV Service Manual 7-5
FUEL SYSTEM
FUEL SYSTEM OPERATION Fuel Injection Pump
Note: Parts breakdown is for reference only.
The following describes the operation of the fuel
injection pump and fuel injector.
* NEVER remove or attempt to remove
the tamper-proof devices from the
high-speed throttle limit screw. This
adjustment has been made at the
factory to meet all applicable
emissions regulations and then (10)
sealed.
* DO NOT attempt to remove or adjust 9
the fuel limiter assembly. (11)
* NEVER attempt to make adjustments
я 0002430
to any sealed adjustment screw.
1 — Fuel Delivery Valve
* Any alterations to this engine may 2 — O-Ring
affect the warranty coverage of this 3 —Body
engine. 4 — Fuel Plunger
oo , 5 -Gasket
* See Yanmar Limited Warranty in 6 — Alignment Pin
Section 2. 7 —Base Plate
| 0000174en | 8 —Fuel Control Lever
9 —Pin
10— Spring Seat
11- Spring
12- Spring Retainer
Figure 7-1
Note: While the parts catalog shows the
individual service parts for the fuel
injection pump, the fuel injection pump is
not intended to be serviceable. Do not
disassemble the fuel pump. lf the fuel
injection pump is faulty, replace it with a
new fuel injection pump assembly.
The fuel injection pump is a very important
component of the engine. It is capable of making
very precise fuel delivery adjustments according to
the varied loads applied to the engine.
7-6 LV Service Manual
FUEL SYSTEM
The fuel delivery valve (Figure 7-2, (5)) connects to Fuel Injector
a high-pressure fuel injection line that is attached to
the fuel injector. The plunger is activated by a (1)
tappet (Figure 7-2, (6)) that rides on a special lobe |
(Figure 7-2, (7)) of the camshaft. The shape of the
fuel injection lobe prevents the engine from
operating in the reverse direction. A spring
(Figure 7-2, (2)) keeps the tappet in contact with
the camshaft lobe. Proper fuel injection timing is
adjusted by the thickness of a shim
(Figure 7-2, (8)) installed between the fuel injection
pump and the crankcase mounting surface.
000000
©
(5)
y
(7)
|
1 ~ Injector Body
2 — Alignment Pin
3 — Pressure Adjusting Shims
4 — Spring
5 — Spring Seat
6 — Valve Stop Spacer
7 —Nozzle Body and Valve
8 — Nozzle Case Nut
+
0002429
Figure 7-3
0002455A The fuel injector is essentially a spring-loaded
valve. When fuel pressure from the fuel injection
Figure 7-2 pump reaches a predetermined level, the pintle
Fuel from the fuel tank to the fuel injection pump is (valve) is forced off its seat and fuel is atomized as
delivered either by gravity or a low-pressure fuel it passes о etween the pintle and seat. The timing
pump. Engine speed is controlled by a centrifugally and quantity of the fuel injected into the cylinder is
operated governor assembly that acts directly controlled by the fuel injection pump and governor
against the control lever (Figure 7-2, (3)). assembly.
Fuel to be injected into the cylinder is pressurized
by the up and down motion of the camshaft-driven
plunger (Figure 7-2, (1)) within the body
(Figure 7-2, (4)), through the fuel supply valve, and
is then supplied by the high-pressure fuel injection
line to the fuel injector.
LV Service Manual 7-7
FUEL SYSTEM
FUEL SYSTEM DIAGRAM
(1)
>
В
2 | (6)
(2) —_ = Pe
Y
8) (4) a
0002436 |
1 —Diesel Fuel Supply 4 — High-Pressure Fuel Injection Line
2 — Fuel Filter 5 —Fuel injector
3 — Fuel Injection Pump 6 —Fuel Return from Fuel Injector
Figure 7-4
7-8 LV Service Manual
FUEL SYSTEM
FUEL SYSTEM COMPONENTS
Typical (Components may vary by engine model and engine application)
00024288
1 ~Fuel Filler Cap and Gasket 8 ~Fuel Supply Line
2 — Fuel Filler Strainer 9 — Fuel injection Pump
3 — Fuel Filter 10—High-Pressure Fuel injection Line
4 — Fuel Filter Gasket 11 — Fuel Injection Line Support
5 — Fuel Tank (Typical) 12— Fuel Injector
6 —Drain Plug 13-Return Fuel Hose
7 —Fuel Shut-Off Valve
Figure 7-5
LV Service Manual 7-9
FUEL SYSTEM
CHECKING AND ADJUSTING
FUEL INJECTION TIMING
Checking Fuel Injection Timing
Note: Some fuel may drain from the fuel
injection pump during this process. Make
provisions to contain spills.
1. Verify actual piston TDC. See Checking Actual
Piston TDC (Top Dead Center) on page 6-36.
2. Ensure the fuel injection pump is primed
with fuel. See Priming the Fuel System on page
4-14.
Note: If the engine is removed from the
equipment, attach a “temporary” fuel
supply to the fuel injeciton pump inlet.
3. Remove the cooling fan housing and recoil
starter.
4. Highlight the TDC timing mark on the cylinder
cooling fin (Figure 7-6, (1)).
5. Highlight the TDC (Top Dead Center)
(Figure 7-6, (2)) and target timing
(Figure 7-6, (3)) marks BTDC (Before Top
Dead Center) on the flywheel timing grid
(Figure 7-7) based on the Fuel Injection Timing
Chart (Figure 7-8).
LR Ni Y A A
Ta а
| EN — — 0002470A
Figure 7-6
7-10
Y Y Y Y Wa
P— y
BTDC
1 \
TDC 5° 0°
— E
/ й а [Г J
Figure 7-7
Fuel Injection Timing Chart
Engine Injection Timing BTDC
L48V 17.5 + 0.5°
L70V 16.0 + 0.59
L100V 15.5 + 0.59
Figure 7-8
6. Clean the areas around the fuel injection pump
and fuel injector to prevent contamination when
the fuel injection line is removed.
IMPORTANT
Always use a wrench to hold the fuel
infection pump fuel delivery valve to prevent
loosening of the delivery valve when
loosening or tightening the high-pressure
fuel injection lines. |
Note: To prevent “rounding” the fuel line nuts
always use a “line” or “flare nut” wrench.
7. Remove the high-pressure fuel injection line.
8. Set the throttle control lever to the minimum
speed position.
9. Remove the nut (Figure 7-9, (2)) fastening the
injection pump inspection window cover plate
(Figure 7-10, (1)). Remove the inspection
cover plate and gasket.
LV Service Manuai
FUEL SYSTEM
00045790
Figure 7-9
10. Install the fuel adjustment jig (Figure 7-10, (2)),
Yanmar P/N 114771-92310, in the fuel injection
pump inspection window. Using the inspection
window cover plate nut, fasten the fuel
adjustment jig aligning the upper left edge of
the jig (Figure 7-10, (4)) to the alignment mark
scribed on the face of the fuel injection pump
(Figure 7-10, (1)) base plate (Figure 7-10, (3)).
Note: Be sure to keep the fuel adjustment jig
parallel to the inspection window
opening. (Figure 7-10 shows the
alignment mark for clarity only. The edge
of the jig should be directly on the mark
when installed properly.)
To assist in the alignment of the fuel
adjustment jig, tighten the attaching nut
to just hold the jig "lightly" in place. Then
"lightly" tap the jig into the proper
position. Once the jig is in position,
tighten the attaching nut to hold the jig
firmly in place.
LV Service Manual
0004579
Figure 7-10
11. Set the throttle control lever to the maximum
speed position.
12. Install the spill-timing tool (Figure 7-11, (1))
onto the fuel delivery valve. See Measuring
Instruments on page 7-5, for a description of
the tool.
(1)
0002454C
Figure 7-11
Note: If a timing tool is not available, timing can
be checked by watching the fuel level
movement in the delivery valve outlet.
7-11
FUEL SYSTEM
13. Turn on the fuel supply to the fuel injection
pump. |
14. Rotate the flywheel / crankshaft clockwise until
fuel is pumped from the nozzle of the
spill-timing tool.
Note: The fuel injection pump pumps fuel to
the fuel injector only once every two
engine revolutions.
15. Slowly rotate the flywheel / crankshaft
clockwise until the TDC mark on the flywheel is
at approximately the 9 o'clock position.
16. Lightly “Flick” the timing tool nozzle with your
finger to remove bubbles and establish a fuel
level at approximately half the height of the
nozzle (Figure 7-11, (2)).
17. Very slowly rotate the crankshaft clockwise until
the fuel level in the nozzle of the spill-timing
tool, or in the delivery valve, just begins to
move. Immediately stop rotating the crankshaft.
If no fuel movement is noticed, rotate the
flywheel clockwise until the TDC mark is again
at the 9 o'clock position and repeat the process.
18. Without moving the flywheel, insert a wooden
wedge between the flywheel and the engine
crankcase to hold the flywheel stationary.
19. Check the position of the flywheel target timing
mark (Figure 7-12, (1)) on the flywheel grid in
relation to the TDC timing mark
(Figure 7-12, (2)) on the crankcase cooling fin.
* |f the two marks are aligned, the fuel injection
timing is correct. Proceed to Step 21.
* |fthe marks do not align, adjust the fuel
injection timing. Do not rotate the flywheel and
proceed to Adjusting Fuel Injection Timing on
page 7-13.
0002474C
1 — Target Timing Mark
2 -TDC Timing Mark
3 - ТОС -Тор Dead Center
Figure 7-12
IMPORTANT
Always turn the crankshaft in a clockwise
direction when checking fuel injection
timing.
20. Repeat steps 15-20 two or three times to verify
timing.
21. Remove the spill-timing tool.
22. Remove the wooden wedge.
IMPORTANT
Always use a wrench to hold the fuel
injection pump fuel delivery valve to prevent
loosening of the delivery valve when
loosening or tightening the high-pressure
fuel injection lines.
Note: To prevent “rounding” the fuel line nuts
always use a “line” or “flare nut” wrench.
23. Install the high-pressure fuel injection line and
tighten to specifications. See Special Torque
Specifications on page 7-4.
24. Install the cooling fan housing and recoil.
25. Prime the fuel system. See Priming the Fuel
System on page 4-14. Operate the engine and
check for fuel leaks.
LV Service Manual
FUEL SYSTEM
Adjusting Fuel Injection Timing
If the timing marks did not align when performing
the Checking Fuel Injection Timing procedure on
page 7-10, perform the following steps to properly
time the engine.
1. If not already completed, verify actual piston
TDC, See Checking Actual Piston TDC (Top
Dead Center) on page 6-36.
2. Leave the adjustment jig and the spill-timing
tool installed on the fuel injection pump. Return |
the throttle control lever to the minimum speed |
position.
(
N=
ZN 00024718
1 -TDC Timing Mark
2 —Measured Timing Mark (Timing
3. Ensure the wooden wedge is in place and the
flywheel has not rotated since the timing check
procedure. Retarded)
4. Observe the difference between the "actual" 3 —Target Timing Mark (15°)
timing setting and the "target" timing setting. 4 —Measured Timing Mark (Timing
e Mih dtimi k (Fi 7-13. (2 Advanced)
| the measure timing mark (Figure 7-13, (2)) 5 -TDC -Top Dead Center
is closer to TDC (Figure 7-13, (5)) than the
target timing mark (Figure 7-13, (3)), the Figure 7-13
timing is “retarded” and must be advanced. To | |
required to correct the timing. Each 0.004 in.
(0.1 mm) thickness change will result in 1°
timing change.
* |fthe measured timing mark (Figure 7-13, (4))
is further from TDC than the target timing mark
(Figure 7-13, (3)), the timing is “advanced”
and must be retarded. To retard the timing, Note: Shims are available in a set, including
increase shim thickness. one each of the following thicknesses
0.008 in. (0.20 mm), 0.010 in. (0.25 mm),
0.012 in. (0.30 mm) and
0.014 in. (0.35 mm). You may use
multiple shim sizes to reach the desired
timing setting. The shims are not
marked, so you will have to measure
them with a micrometer.
6. Remove the fuel injection pump, see (Removal
of Fuel Injection Pump on page 7-15) and the
shim(s) from between the fuel injection pump
and the engine crankcase. Measure and record
the thickness of the existing shim(s).
LV Service Manual 7-13
FUEL SYSTEM
Example:
Subject engine - L70V
Target timing = 15° + 0.5° BTDC
Measured timing = 10° BTDC (5° retarded)
Calculate the timing difference: 15° - 10° = 5°
Determine the difference in shim thickness:
Where: 0.004 in. (0.1 mm) = 1°
5° x 0.004 in.(0.1 mm) = 0.020 in. (0.5 mm)
In this case, the timing was “retarded” so the
desired total shim(s) thickness needs to be 0.020
in. (0.5 mm) thinner than the original shim(s).
Measuring with a micrometer, if the existing shim(s)
thickness is 0.048 in. (1.20 mm), the new thickness
should be:
(0.048 in.- 0.020 in. = 0.028 in.) 2 x 0.014 in. shims
= 0.028 in. total shims. (Equals 15 degrees BTDC)
or
(1.20 mm - 0.5 mm = 0.70 mm) 2 x 0.35 mm shims
= 0.70 mm total shims. (Equals 15 degrees BTDC)
7. Install the calculated shim(s) (Figure 7-14, (1))
over the injection pump mounting studs and
onto the crankcase mounting surface. Note: Do
not use any sealant for this assembly.
(1)
0002455
Figure 7-14
7-14
8. Install the fuel injection pump. Take up any
slack in the mounting hardware by manually
rotating the injection pump clockwise as you
tighten the injection pump mounting nuts.
9. Tighten the fuel injection pump mounting nuts
to specification. See Special Torque
Specifications on page 7-4.
10. Remove the wooden wedge and repeat the
timing procedures. See Checking Fuel Injection
Timing on page 7-10 and Adjusting Fuel
Injection Timing on page 7-13 until fuel injection
timing is correct.
11. When the timing is correctly set, remove the
fuel adjustment jig and spill-timing tool and the
wooden wedge.
12. Reinstall the injection pump inspection cover
and gasket. Tighten the mounting nut to
specification. See Special Torque
Specifications on page 7-4.
IMPORTANT
Always use a wrench to hold the fuel
injection pump fuel delivery valve to prevent
loosening of the delivery valve when |
loosening or tightening the high-pressure
fuel injection lines.
Note: To prevent “rounding” the fuel line nuts,
always use a “line” or “flare nut” wrench.
13. Install the high-pressure fuel injection line and
tighten to specifications. See Special Torque
Specifications on page 7-4.
14. Install the cooling fan housing and recoil.
15. Prime the fuel system. See Priming the Fuel
System on page 4-14. Operate the engine and
check for fuel leaks.
LV Service Manual
FUEL SYSTEM
FUEL INJECTION PUMP
Removal of Fuel Injection Pump
ALWAYS wear SAFETY GLASSES while
servicing the engine to prevent possible
eye injury.
0000013en
Note: Be sure the speed control lever is set to
1.
the SLOW-IDLE position before
removing the fuel injection pump.
Clean the areas around the fuel injection pump
(Figure 7-15, (6)) and fuel injector.
Close any fuel valves in the fuel supply line.
IMPORTANT
Always use a wrench to hold the fuel
injection pump fuel delivery valve to prevent
loosening of the delivery valve when
loosening or tightening the high-pressure
fuel injection lines.
Note: To prevent “rounding” the fuel line nuts,
always use a “line” or “flare nut” wrench.
3. Remove the high-pressure fuel injection line
(Figure 7-15, (1)). Use care not to bend the
line.
Remove the fuel supply line (Figure 7-15, (2)).
Plug or cap all openings to minimize leaks and
prevent contamination.
Remove the three nuts (Figure 7-15, (5))
fastening the fuel injection pump into the
cylinder block.
LV Service Manual
©
1)
Figure 7-15
7. Remove the inspection cover (Figure 7-15, (3))
and gasket (Figure 7-15, (4)).
Remove the fuel injection pump (Figure 7-16).
0001830
Figure 7-16
Remove the shim(s) (Figure 7-15, (7)). Use
care not to bend or damage the shim(s).
Note: The L48V model engines use a flat
tappet.
The L70V and L100V model engines use
a roller tappet.
7-15
FUEL SYSTEM
10. Remove the fuel injection pump tappet
(Figure 7-15, (8)) from the crankcase. The
tappet may stay in the cylinder block. You can
remove it with your finger. Inspect the face or
roller end of the tappet for damage or abnormal
wear. See Tappet on page 6-50.
Note: The fuel injeciton pump is not designed
to be tested or serviced. Do not
disassemble the fuel injection pump. If
the fuel injection pump requires
servicing, it must be replaced with a new
fuel injection pump. 00024388
Figure 7-18
Installation of Fuel injection Pump
1. Adjust the throttle control so the governor lever
(Figure 7-17, (1)) fork is positioned in the
center of the fuel injection pump opening.
|
5. Install the two side mounting nuts
(Figure 7-19, (5)) and tighten to specification.m
See Special Torque Specifications on page 7-4.
Note: If the original fuel injection pump,
camshaft and injection pump tappet
(Figure 7-19, (8)) are being reused, you
do not need to recheck the fuel injection
(1) — timing. If any of these components have
been replaced, it will be necessary to
check the fuel injection timing. See
|
LL
Checking and Adjusting Fuel Injection
an Timing on page 7-10.
0002473
Figure 7-17
2. Install the fuel injection tappet.
3. Install the original fuel injection pump shim(s)
(Figure 7-19, (7)).
4. Install the fuel injection pump (Figure 7-19, (6))
into the crankcase, ensuring that the fuel
injection pump lever pin (Figure 7-18, (1)) is
engaged in the governor lever fork
(Figure 7-18, (2)).
Hold the injection pump against the crankcase
and move the speed control. Make sure the fuel
injection pump control lever also moves.
To reduce any play in the mounting hardware,
manually rotate the fuel injection pump clockwise
while tightening the mounting nuts.
7-16 | LV Service Manual |
FUEL SYSTEM
6.
Install the inspection cover (Figure 7-19, (3)),
gasket (Figure 7-19, (4)) and nut. Tighten to
specification. See Special Torque
Specifications on page 7-4.
IMPORTANT
Always use a wrench to hold the fuel
injection pump fuel delivery valve to prevent
loosening of the delivery valve when
loosening or tightening the high-pressure
fuel injection lines.
Note: To prevent “rounding” the fuel line nuts,
7.
always use a “line” or “flare nut” wrench.
Install the fuel injection high-pressure fuel
injection line (Figure 7-19, (1)). Tighten the
nuts to specification. See Special Torque
Specifications on page 7-4.
Install the fuel supply line (Figure 7-19, (2)).
Prime the fuel system. See Priming the Fuel
System on page 4-14.
10. Operate the engine and check for fuel leaks.
LV Service Manual
Replacement and/or Adjustment of
the Fuel Limiter
If the fuel limiter (Figure 7-20, (1)) is damaged, or it
is obvious the fuel limiter adjustment has been
tampered with, it will be necessary to replace
and/or adjust the fuel limiter using the following
procedure.
a
(1)
N
0004580A
Figure 7-20
IMPORTANT
This is an emissions related procedure. Follow
the procedure carefully to assure emissions
compliance. It is good service practice to always
Keep good service records.
If you are replacing the fuel injection pump, replace
it before continuing with the fuel limiter replacement
and/or adjustment procedure". See Installation of
Fuel Injection Pump on page 7-16. Do not install
the inspection window cover and gasket at this
time.
1. Confirm that the fuel injection timing is correct.
Adjust the fuel injection timing if needed. For
the fuel injection timing procedure. See
Checking Fuel Injection Timing on page 7-10
and Adjusting Fuel Injection Timing on page 7-
13.
7-17
FUEL SYSTEM
2. Install the fuel adjustment jig (Figure 7-21, (2)),
Yanmar P/N 114771-92310, in the fuel injection
pump inspection window. Using the inspection
window cover plate nut, fasten the fuel
adjustment jig aligning the upper left edge of
the jig (Figure 7-21, (4)) to the alignment mark
scribed on the face of the fuel injection pump
(Figure 7-21, (1)) base plate (Figure 7-21, (3)).
Note: Be sure to keep the fuel adjustment jig
parailel to the inspection window
opening. (Figure 7-21 shows the
alignment mark for clarity only. The edge
of the jig should be directly on the mark
when installed properly.)
To assist in the alignment of the fuel
adjustment jig, tighten the attaching nut
to just hold the jig "lightly" in place. Then
"lightly" tap the jig into the proper
position. Once the jig is in position,
tighten the attaching nut to hold the jig
firmly in place.
M—
a - @
DA
0004579
Figure 7-21
With the fuel adjustment jig in place, replacement
or adjustment of the fuel limiter can continue.
7-18
ALWAYS wear SAFETY GLASSES while
servicing the engine to prevent possible
eye injury.
000001 3en
Note: When replacing or adjusting the fuel
limiter, a new fuel limiter tamper-proof
cover and lock plate must be used. Using
the correct parts catalog for the specific
engine you are working on to order these
parts.
3. To remove the tamper-proof cover from the fuel
limiter, use a hacksaw or a cut-off wheel to
carefully make a small slot (Figure 7-22, (2)) in
the side of the tamper-proof cover
(Figure 7-22, (1)).
J
3)
Figure 7-22
0004580
Note: Be careful not to damage the cylinder
block boss (Figure 7-22, (3)) when
removing the tamper-resistant cover.
LV Service Manual
FUEL SYSTEM
4. Use a hammer and metal chisel
(Figure 7-23, (2)) to drive off the tamper-
resistant cover (Figure 7-23, (1)). The chisel
should be held at about a 30° angle to the
tamper-resistant cover, and engaged in the slot.
Discard the old tamper-resistant cover.
o | 8
[= -
/
/ (2)
Figure 7-23
N°
Fa
5. If installing a new fuel limiter, remove the
original fuel limiter assembly from the threaded
boss in the cylinder block. Disassemble the
original fuel limiter assembly Figure 7-24 and
discard the fuel limiter (Figure 7-24, (2)) and
lock plate (Figure 7-24, (1)).
6. Reassemble the fuel limiter assembly with the
new fuel limiter and the new lock plate.
Note: If the original fuel limiter is to be reused,
the only part needing replacement is the
lock plate.
or
TTD
=
(1)
0004582
Figure 7-24
7. Assemble the new fuel limiter assembly
Figure 7-25 without the new tamper-resistant
cover.
LV Service Manual
0004583
Figure 7-25
8. Thread the new fuel limiter assembly into the
cylinder block boss until the threads on the fuel
limiter extend about 0.250 in. (6.35 mm) past
the surface of the cylinder block boss. Thread
on the fuel limiter locking nuts, but do not
tighten at this time.
Note: The fuel limiter is equipped with a
"thermostat-like" wax pellet that
contracts when cold, supplying more fuel
for cold starting. When the engine
reaches operating temperature, 30°C
[86°F] or greater, the fuel limiter tip
extends by 0.9 mm to return to the
normal fuel setting.
IMPORTANT
Do not use an open flame to heat the fuel
limiter.
9. To adjust the fuel limiter, heat the rear portion of
the fuel limiter with a hot air gun or hair dryer to
assure that it is above 30°C [86°F], so the fuel
limiter pin will be fully extended.
10. Rotate the speed control lever fully clockwise
until it stops. Before proceeding, check that the
tip of the fuel limiter is not touching the control
lever (Figure 7-26, (1)).
7-19
FUEL SYSTEM
L48V Models:
* Thread the fuel limiter into the crankcase boss
until the fuel limiter pin just touches the control
lever. Do not depress the fuel limiter pin.
L70V Models,
* Adjust the fuel limiter using the same
procedure as the L48V above. Then move the
speed control lever counter clockwise until the
fuel limiter pin is no longer touching the control
lever. Then turn the fuel limiter "in" an
additional 1/3 turn.
L100V Models
* Adjust the fuel limiter using the same
procedure as the L48V above. Move the speed
control lever counter clockwise away from the
fuel limiter and then turn the fuel limiter "in" an
- additional 1/2 turn.
11. Without changing the adjustment of the fuel
limiter, tighten the fuel limiter mounting nuts to
specifications. See Special Torque
Specifications on page 7-4.
UT 4 Sa AV
Мо ff PS
BL
woot
un
iv
SRY
A. | iu
(1)
0004584
Figure 7-26
7-20
12. Remove the fuel adjustment jig from the fuel
injection pump. Install the inspection window
cover plate using a new gasket and tighten the
nut to specifications. See Special Torque
Specifications on page 7-4.
13. Install the new fuel limiter tamper resistant
cover (Figure 7-27, (1)). Do not reuse the old
cover. Use a soft-faced hammer to "tap" the
tamper-resistant cover into place. When
properly installed, there should not be a gap
(Figure 7-27, (2)) between the tamper-resistant
cover and the cylinder block mounting boss
(Figure 7-27, (3)).
MD i
М
(3)
(2) 0004585
Figure 7-27
LV Service Manual
FUEL SYSTEM
FUEL INJECTOR
Removal of Fuel Injector
1.
Close any fuel valves in the fuel supply line.
IMPORTANT
Always use a wrench to hold the fuel
injection pump fuel delivery valve to prevent
loosening of the delivery valve when
loosening or tightening the high-pressure
fuel injection lines.
Note: To prevent “rounding” the fuel line nuts,
4.
5.
always use a “line” or “flare nut” wrench.
Remove the high-pressure fuel injection line.
Disconnect the fuel return hose from the fuel
injector.
Remove the fuel injector retainer plate
(Figure 7-28, (1)).
Remove the fuel injector from the cylinder head.
If the fuel injector “sticks” in the cylinder head,
reinstall the high-pressure fuel injection line and pry
up on the fuel line nut.
(1)
à A E
ql
Е Mm
(2) 0001847
Figure 7-28
LV Service Manual
Remove the injector nozzle gasket
(Figure 7-28, (2)) and spacer
(Figure 7-28, (3)). If the injector nozzle gasket
and spacer remain in the cylinder head, remove
them from the cylinder head by threading an 8
mm or 9 mm bolt, at least 200 mm long, into the
gasket. Use the bolt as a puller. Discard the
gasket.
7-21
FUEL SYSTEM
Testing of Fuel Injector 1. Thoroughly clean the fuel injector nozzle using
clean diesel fuel and a brass wire brush.
2. Visually inspect the fuel injector nozzle for
deposits or damage. Clean, repair or replace as
| Never use a steel wir sh to clean
steel wire bru necessary.
fuel injectors. Damage to the nozzle and
other components is likely to result. Note: Test the fuel injector using an injection
nozzle tester (Figure 7-29). Operate the
tester following the information provided
by the tester manufacturer. Use clean,
filtered fuel or FIE calibration fluid for the
test.
0000172en
3. Using the correct adapter, connect the fuel
injector to a nozzle tester. Aim the fuel injector
| into a suitable container to contain the fuel
spray.
ALWAYS wear SAFETY GLASSES while
servicing the engine to prevent possible
eye injury.
0000013en
00005818
ай Figure 7-29
HIGH-PRESSURE HAZARD! 4. Pump the operating lever of the tester slowly,
observing the pressure reading at the point
where the fuel injector begins spraying fuel.
See Test and Adjustment Specifications on
page 7-4, for correct pressure readings.
e Avoid skin contact with the
high-pressure diesel fuel spray caused
by a fuel system leak such as a broken
fuel injection line. High-pressure fuel
can penetrate your skin and result in Note: Opening pressure of a new fuel injector
serious injury. If you are exposed to will be approximately 72.5 psi (0.5 MPa,
high-pressure fuel spray, obtain 5 kgf/cm?) higher than one that has been
prompt medical treatment. operated for five hours or longer.
* NEVER check for a fuel leak with your
hands. ALWAYS use a piece of wood
or cardboard. Have your authorized
Yanmar industrial engine dealer or
distributor repair the damage.
* Failure to comply could result in death
or serious injury.
0000008en
7-22 | LV Service Manual
FUEL SYSTEM
5. Pump the operating lever slowly to hold the Disassembly and Inspection of Fuel
pressure steady at a point just below the Injector
opening pressure and hold for five seconds.
Observe the injector to see that it is sealing
properly and is not “dripping.” If fuel leaks from
the return fuel line fitting, check that the nozzle
case nut is tight. Repair or replace the fuel
injector if fuel continues to leak from either the
return line fitting or nozzle.
6. Pump the operating lever more rapidly to
repeatedly “pop” the injector and observe the
spray pattern. The pattern should be a very fine
uniform spray (Figure 7-30). If a dripping or an
uneven pattern is seen (Figure 7-31), service
or replace the injector.
Never use a steel wire brush to clean
fuel injectors. Damage to the nozzle and
other components is likely to result.
0000172en
1. Clean carbon from used injectors using clean
diesel fuel. Hardened deposits or varnish can
be cleaned using a brass wire brush.
0001336A
Figure 7-30
0002429
1 —Injector Body
2 — Alignment Pin
= TD 3 — Pressure Adjusting Shims
4 — Spring
0001337 5 —- Spring Seat
Figure 7-31 6 — Valve Stop Spacer
7 — Nozzle Body and Valve
If the fuel injector fails any of these tests, it should 8 — Nozzle Case Nut
be serviced or replaced as necessary. If the
pressure is outside specified limits, adjust the Figure 7-32
pressure. See Adjusting Fuel Injector Pressure on
page 7-24. | 2. Place the fuel injector in a soft-jawed vise with
the nozzle pointing up.
3. Remove the nozzle case nut.
4. Carefully remove the injector from the vise.
7 4 LV Service Manual 7-23
FUEL SYSTEM
5. Turn the injector over and remove the nozzle Replace the fuel injector assembly if it fails any
body, nozzle valve, valve stop spacer, nozzle Inspection.
spring seat, nozzle spring and shims.
6. Inspect the sealing surfaces (Figure 7-33, (2)) Adjusting Fuel Injector Pressure
between the valve stop spacer and nozzle body The fuel injectors open when pressure reaches a
for nicks or scratches. Check the contact area predetermined pressure threshold. They close
between the valve stop spacer and the nozzle when the pressure is reduced below that threshold.
valve (Figure 7-33, (1)) for scoring or pitting. The pressure threshold can be adjusted by adding
Use a magnifying glass to inspect. or removing shims (Figure 7-35, (3)).
(1)
e
Lu
at
(2)
< o
0001333A
Figure 7-33
7. Perform a nozzle valve slide test:
(a) Wash nozzle body and valve in clean diesel
0002429
fuel. :
1 — Injector Body
(b) While holding the nozzle body vertical, pull 2 — Alignment Pin
the nozzle valve about two-thirds of the way 3 — Pressure Adjusting Shims
out (Figure 7-34). | 4 — Spring
5 — Spring Seat
6 — Valve Stop Spacer
7 -Nozzle Body and Valve
8 —-Nozzle Case Nut
(c) Manually move the nozzle valve up and
down in the nozzle body. It should move
smoothly with no binding.
Figure 7-35
Note: The injection pressure will change by
approximately
284 psi (1.96 MPa, 20 kgf/cm?) for every
0.004 in. (0.1 mm) shim thickness. Add a
shim(s) to increase the injector opening
pressure. Remove a shim(s) to decrease
injector opening pressure.
0001332A
Figure 7-34
See the paris catalog for available shims.
7-24 LV Service Manual
FUEL SYSTEM
Disassemble the fuel injector assembly. See
Disassembly and Inspection of Fuel Injector on
page 7-23.
Remove or add adjusting shims as needed.
Assemble the fuel injector assembly. See
Reassembly of Fuel Injector on page 7-25.
Retest the fuel injector. See Testing of Fuel
Injector on page 7-22. If the injector cannot be
adjusted to the appropriate pressure, discard
and replace the fuel injector.
Reassembly of Fuel Injector
1.
Secure the fuel injector in a soft-jawed vise with
the nozzle end up.
Install the shims, nozzle spring, hozzle spring
seat, valve stop spacer, nozzle valve and
nozzle body.
Install the nozzle case nut. Tighten it to
specification. See Special Torque
Specifications on page 7-4.
Installation of the Fuel Injector
1.
Install a new nozzle spacer (Figure 7-36, (3))
and gasket (Figure 7-36, (2)) on the fuel
injector.
See the parts catalog for correct part number(s).
2.
Install the fuel injector in the cylinder head.
Align the alignment pin with the groove in the
cylinder head and high-pressure outlet as
shown, then push the fuel injector into place.
(1)
=
(3) a I ul
Cd
SPS IA
0001847
Figure 7-36
« LV Service Manual
3.
Install the injector retainer plate
(Figure 7-36, (1)) and tighten the nuts to
specification. See Special Torque
Specifications on page 7-4.
IMPORTANT
Always use a wrench to hold the fuel
injection pump fuel delivery valve to prevent
loosening of the delivery valve when
loosening or tightening the high-pressure
fuel injection lines.
Note: To prevent “rounding” the fuel line nuts,
4.
always use a “line” or “flare nut” wrench.
Install the high-pressure fuel injection line.
Tighten to specifications. See Special Torque
Specifications on page 7-4.
Install the return fuel hose.
Prime the fuel system. See Priming the Fuel
System on page 4-14.
Operate the engine and check for fuel leaks.
7-25
FUEL SYSTEM
SPEED CONTROL DEVICE
Four different speed control designs are available
on the LV Series engine, depending on engine
model and intended usage. The position where the
governor springs are installed differs depending on
the rated rpm and the design of the speed control.
For removal and installation of the L48V model
speed control device. See Replacement of Throttle
Shaft Seal - L48V Models on page 6-56.
For removal and installation of the L70V and L100V
models. See Replacement of Throttle Shaft Seal -
L70V and L100V Models on page 6-57.
Should the high-idle adjustment bolt
(Figure 7-37, (1)) be damaged and require
replacement, or it is obvious that the high-idle
adjustment has been tampered with, use the
following procedure to replace and/or adjust the
high-idle adjustment bolt.
1. Select the replacement parts, as required, and
a new tamper-proof wire and seal from the
parts catalog for the specific engine you are
working on.
2. Operate the engine at no-load full throttle.
Adjust the engine RPM to the correct
specification. See General Engine
Specifications on page 4-6.
3. After adjusting the engine speed to the correct
RPM, install the tamper-proof wire
(Figure 7-37, (2)).
7-26
00046653
Figure 7-37
4. After installing the wire, install and crimp the
tamper-proof seal (Figure 7-37, (3)) onto the
wire.
Use the following charts and graphics
(Figure 7-38) (Figure 7-39) (Figure 7-41)
(Figure 7-42) to determine the correct spring
position for a given engine.
* NEVER remove or attempt to remove
the tamper-proof devices from the
high-speed throttle limit screw. This
adjustment has been made at the
factory to meet all applicable
emissions regulations and then
sealed.
* DO NOT attempt to remove or adjust
the fuel limiter assembly.
* NEVER attempt to make adjustments
to any sealed adjustment screw.
* Any alterations to this engine may
affect the warranty coverage of this
engine.
» See Yanmar Limited Warranty in
Section 2.
0000174en
LV Service Manual
FUEL SYSTEM
Variable Speed Type
The variable speed control device can be moved and locked at any position. This control device can be
converted to operate remotely.
. L48V (Model
Engine L48V6KF9T3E Only) L48V L70V L100V
RPM Rating 3600 rpm 3600 rpm | 3450 rpm | 3600 rpm | 2500 rpm | 3200 rpm | 3600 rpm
Position of 1-B 2-B 2-B 1-B | 1-с 2.8 1-B
Regulator Spring
(2)
0003291
1 -Speed Control Handle 2 — Control Lever
3 - Governor Lever
Figure 7-38
“e LV Service Manual 7-27
FUEL SYSTEM
Remote Control Type
но L48V (Model
Engine L48V6KFOT3E Only) L48V L70V L100V
RPM Rating 3600 rpm 3600 rpm | 3450 rpm | 3600 rpm | 2500 rpm | 3200 rpm | 3600 rpm
Position of 1-B 2-B 2-B 1-B 1-C 2-B 1-B
Regulator Spring
0003292
1 — Control Lever 2 — Governor Lever
Figure 7-39
0003295
3 — Control Lever 4 — Governor Lever
Figure 7-40
7-28 LV Service Manual
FUEL SYSTEM
Variable Speed Friction Plate Type
The variable speed control device can be moved and locked at any position. This control can be converted to
operate remotely.
. L48V (Model
Engine L48V6KF9T3E Only) L48V L70V L100V
RPM Rating 3600 rpm 3600 rpm | 3450 rpm | 3600 rpm | 3600 rpm
Position of 1-B 1-B 1-B 0-B 0-A
Regulator Spring
1 —Speed Control Lever
2 —Friction Control
LV Service Manual
3 — Control Lever
4 — Governor Lever
Figure 7-41
0003293
7-29
FUEL SYSTEM
Constant Speed Type
The constant speed control device is used in applications where a constant engine rpm is wanted, such as
generators. When moved to the full throttle position, the speed control lever “locks” at full throttle.
Engine L48V L70V L100V
RPM Rating 3600 rpm | 3450 rpm | 3600 rpm | 3600 rpm
Position of
Regulator Spring 1-В 15 0-8 ОА
0003294
1 —~ Speed Control Lever 3 — Control Lever
2 — Speed Control Release Lever 4 — Governor Lever
Figure 7-42
7-30 LV Service Manual
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