Yanmar 3JH3E User manual

SERVICE MANUAL
MARINE DIESEi. ENGINE
MODEL
3JH3(B)(C)E494JH3(B)(C)E

Printed in Japan
HINSHI-H8009
FOREWORD
This service manual has been complied for engineers engaged in sales,
service, inspection and maintenance. Accordingly, descriptions of the
construction and functions of the engine are emphasized
in this manual
while items which should already be common knowledge are omitted.
One characteristic of a marine diesel engine is that its performance in a
vessel
is governed by the applicability of the vessel's hull construction
and its steering system.
Engine installation, fitting out and propeller selection have a substantial
effect
on the performance of the engine and the vessel. Moreover, when
the engine runs unevenly or when trouble occurs, it
is essential to check
a wide range of operating conditions -such
as installation to the hull
and suitability of the ship's piping and propeller -and not just the engine
itself. To get maximum performance from this engine, you should com-
pletely understand its functions, construction and capabilities, as well
as proper use and servicing.
Use this manual as a handy reference
in daily inspection and mainte-
nance, and
as a text for engineering guidance.
Model 4JH3E has been used for the illustrations
in this service manual,
but they apply
to models 3JH3E, 3JH3BE, 3JH3CE, 4JH3BE, and 4JH3CE
as well.
METRIC
ALL DIMENSIONS IN MILLIMETERS
UNLESS OTHERWISE SPECIFIED
The contens of this service manual may not be copied or
reproduced without permission.

MODELS
3JH3(B)(C)E49 4JH3(B)(C)E
Chapter 1 GENERAL
1. Exterior Views···················································1-1
2. Specifications ···················································1-3
3. Engine Outling ················································1-6
4. Piping Diagrams ·············································1-10
Chapter 2 INSPECTION AND SERVICING OF
BASIC ENGINE PARTS
1. Cylinder Block···················································2-1
2. Cylinder Head·················································· ·2-4
3. Piston and Piston Pins ····································2-11
4. Connecting Rod ·············································2-15
5. Crankshaft and Main Bearing ···························2-18
6. Camshaft and Tappets ····································2-21
7. Timing Gear ···················································2-24
8. Flywheel and Housing··· .................................... 2-26
Chapter 3 FUEL INJECTION EQUIPMENT
1. Fuel injection Pump Service Data ...... ·...··...··...··· ·3-1
2. Governor ··..·..·..·..····..·..····..·..··············..······..··3-4
3. Disassembly, Reassembly and Inspection of
Fuel injection pump .......................................... 3.14
4. Adjustment of Fuel Injection Pump and Governor ···3-24
5. Fuel Feed Pump ............................................. 3.30
6. Fuel injection Nozzle ············ ........................... 3.32
7. Troubleshooting ······ ....................................... 3.35
8. Tools ............................................................ 3.35
9. Fuel Filter · ....... ········......·· ........ ··.....·..·······..···3-40
10.Fuel Tank ...................................................... 3.41
11.Troubleshooting ···················· ......................... 3.42
Chapter 4 INTAKE AND EXHAUST SYSTEM
1. lntank System ........ ·.... ·········· ... ······ .....·-·.....·..... 4.1
2. Exhaust System ....·· ............. ·...···...··...·······..·....4.2
Chapter 5 LUBRICATION SYSTEM
1. Lubrication System ........ ······ ........ ······...··...····· ·5-1
2. Lube Oil Pump ................ · ............ ·....····· ....... ··5-2
3. Lube Oil Filter ··...·····...·..······ .......... ·....··...·····...·5-6
4. Lube Oil Cooler .................................. ·· .......... ··5-8
5. Rotary Waste Oil Pump (Optional) ·············· .......... 5.9
Chapter 6 COOLING WATER SYSTEM
1. Cooling Water System .......... ···..·· ...................... 5.1
2. Sea Water Pump ............................................. 5.3
3. Fresh Water Pump···································· ......... 5.5
4. Heat Exchanrger ..·......·..·......··....·..··...··...·······6-8
5. Pressure Cap and Sub Tank .............................. 5.10
6. Thermostat ········..····..·······..·..·..··....··············6-12
7. Bilge pump and Bilge Strainer (Optional) ............ 5.14
Printed in Japan
HINSHI-H8009
Chapter 7 REDUCTION AND REVERSING GEAR
Marine Gear Models [KM3A]
1. Construction ................................................... 7.1
2. Shifting Device ·......···············..·····......···...·······7-7
3. Inspection and Servicing ................ ······...· ....... ···7-12
4. Disassembly ································· ............... 7.20
5. Reassembly ................................................... 7.25
Marine Gear Models [KM3P)
1. Construction ······· ......................................... 7.29
2. Shifting Device ................................................ 7.35
3. Inspection and Servicing·····..... ········ .....···· ....... ··7-40
4. Disassembly ................................................ 7.45
5. Reassembly ..···.....· .............. · .................. ·······7-53
Chapter 8 REMOTE CONTROL (OPTIONAL)
1. Remote Control System .................................... 5.1
2. Remote Control Installation ................................. 8-2
3. Remote Control Inspection ................................. 5.4
4. Remote Control Adjust ment .....············...·····....·8-5
Chapter9 ELECTRICAL SYSTEM
1. Electrical System ....... ··....· ......... · ............ ··...... ·9-1
2. Battery ............................................................ 9.5
3. Starter Motor ..···.....···· ........... ··....·......····....··...9.5
4. Alternator Standard, 12V/55A ······························9-22
5. Alternator 12V/80A (OPTIONAL) ........................... 9.30
6. Instrument Panel .................... ··· ............... ·····..9.40
7. Warning Devices ............................................. 9.42
8. Air Heater (Optional) ··········...········· ................. 9.45
9. Electric type Engine Stopping Device (Optional) ······9-46
10.Tachometer ··········· ........................................ 9.45
Chapter 10 DISASSEMBLY AND REASSEMBLY
1. Disassembly and Reassembly Precautions····....····10-1
2. Disassembly and Reassembly Tools .................. 10-2
3. Disassembly and Reassembly··.. ········· .............. 10-14
4. Table of Standard Measurements for Maintenance ···10-35
5. Tightening torque ........... ·····...······ ......... ·····...10-40
6. Test Running ................................................ 10-41
Chapter 11 TROUBLESHOOTING
1. Troubleshooting ............................................. 11-1

Printed in Japan
HINSIII-H8009
CHAPTER 1
GENERAL
1. ExteriorViews ·········································· 1-1
1-1 3JH3E ················································1-1
1-2 4JH3E ····························· ···················1-2
2. Specifications ··········································1-3
2-1 3JH3E, 3JH3BE, 3JH3CE ························1-3
2-2 4JH3E, 4JH3BE, 4JH3CE ························1-4
2-3 Sales condition, Marine gear·····················1-5
3. Engine Outline ··········································1-6
3-1 3JH3E (with KM3P Marine gear) ···············1-6
3-2 3JH3BE (with KM3A Marine gear) ············1-7
3-3 4JH3E (with KM3P Marine gear) ···············1-8
3-4 4JH3BE (with KM3A Marine gear) ············1-9
4. Piping diagrams ·······································1-10
4-1 3,4JH3(B)(C)E ····································1-10

Chapter 1 General
.:.l·:..;E::.:.:,x;;.;te;.;.r;.;io;;.:r....;..V;;.;ie;;.;,w,;.,;s~-------------------------- 3,4JH3(B)(C)E
1. Exterior Views
1-1 3JH3E
• Operation Side Intake manifold
Dipstick
Fuel filter
Marine
gear
Fuel oil pump
Shift !ever
...____ Oil filter cap
Fuel feed
pump
"'Lube oil filter
• Non Operation Side V-be!t Fresh
water tank
Fresh water
pump
Alternator
Exhaust manifold
Starter
motor
Sea water pump
<Note> This illustration shows Yanmar marine gear (Model: KM3P) when it has been attached.
Printed in japan
HINSHI-H8009
1-1

Chapter 1 General
.:,1.:.,. ~E::;:x;;,.:te:;;,:r.,:io:;:;:r~V~ie:;;;.:w:;,;,;s::;_ __________________________ 3.4JH3(B)(C)E
1-2 4JH3E
Dipstick
• Operation Side
Intake manifold
Fuel filter
Marine gear
Fuel oil pump
Shift lever
Oil filter cap
Fuel feed pump
Lube oil filter
Oil Filter cap (Marine gear)
• Non Operation Side
V-belt
Fresh water tank
Fresh water pump
Alternator
Exhaust manifold
Starter motor
~
Sea water pump
<Note> This illustration shows Yanmar marine gear (Model: KM3P) when it has been attached.
1-2
Printed in Japan
HINSHI-H8009

Chapter 1 General
_2.;..S~p~e;..;;c_ifl_1c;..a_t1_·o_n..;;.s __________________________ 3,4JH3(B)(C)E
2. Specifications
2-1 3JH3E, 3JH3BE, 3JH3CE
Model
Type
Combustion system
Aspiration
Number of cylinders
Bore X stroke mm
Displacement
.e
One hour rating Output/crankshaft
speed kW/rpm
(HP/rpm)
output Brake mean effective kgf/cm'
(flywheel output) pressure
Piston speed m/sec.
Continuous rating Output/crankshaft
speed kW/rpm
(HP/rpm)
outpot Brake mean effective
(DIN6270A) kgf/cm'
flywheel output pressure
Piston speed m/sec.
Compression ratio
Fire order
Fuel injection pump
Fuel injection timing degree
(b.T.D.C.)
Fuel injection pressure kg/cm•
Fuel injection nozzle
Direction of (Crankshatt)
rotation
Power take off
Cooling system
Lubrication system
Starting system Starting motor
AC generato
Model
Type
Reduction rate (ahead/astern) iii
Propeller speed (ahead/astern) rpm
Standard propeller
Marine Gear (Dia.
XpitchXnumber)
mm
Propeller shaft dia.
X Countershaft dia. mm
Lubrication system
Lube oil pan ITotal caoacltv
R,
I Effective capacity
i.
Cooling system
Weight [kg]
Overall length mm
Dimensions Overall width mm
Overall height
mm
Engine weight without marine gear (dry)
kg
Lubricating oil capacity Effect/max.
R,
.'
(Note) Rating cond1t1on: ISO -3046/1, 1 HP =;: 0. 7355 kW
Printed in Japan
HINSHI-H8009
3JH3E 3JH38E 3JH3CE
Vertical 4-cycle water cooled diesel engine
Direct injection
Normal aspiration
3
84 X 90
1.496
26.5/3650
(36/3650)
5.93
10.95
29.4/3800
(40/3800)
0.621
(6.33)
11.4
17.7
240"
240'
240"
1 -3 -2 -1
YPES-CL (with Timer}
12·
200±5
Hole type
Counter-clock wise
viewed from stern
At Flywheel side
Constant high temperature fresh water cooling
Fresh water : Centrifugal pump
Sea water :Rubber impeller pump
Forced lubrication with trochoid pump
DC 12V,1.2kW
12V,55A
(12V80A: Option)
KM3P KM3A
(Sail Drive SD-3t can be used)
Mechanical cone clutch Mechanical cone clutch
directly on location.
(torque limiter no angle)
2.361316 2.61/3.16 3.2013.16 2.3313.04 2.64/3.04
--
1610l12031457112031188/1203 1629/1249 1441/1249
--
--
--
Splash
0.35 0.45
--
0.05 0.05
--
--
-- --
[13] [13]
--
755.6 752.8 545.8
520.6 520.6
628.6 628.6
186 173
4.4/1.8 4.9/2.1 4.9/2.1
1-3

Chapter 1 General
~Z_S~p~e~c_m_k~a_u_o_fl_s __________________________ ~4JH~BXC~
2-2 4JH3E, 4JH3BE, 4JH3CE
Engine Model
Type
Combustion system
Aspiration
Number of cylinders
Bore X stroke mm
Displacement
.e
Output/crankshaft kW/rpm
One hour rating speed (HP/rpm)
output Brake mean effective kgf/cm'
(flywheel output) pressure
Piston speed m/sec.
Output/crankshaft kW/rpm
Continuous rating speed (HP/rpm)
outpot Brake mean effective
(DIN6270A) kgf/cm'
flywheel output pressure
Piston speed m/sec.
Compression ratio
Fire order
Fuel mjection pump
Fuel injection timing degree
(b.T.D.C.)
Fuel injection pressure kg/cm'
Fuel injection nozzle
Direction of (Crankshaft)
rotation
Power take off
Cooling system
Lubrication system
Starting system Starting motor
AC generato
Model
Type
Reduction
rate (ahead/astern) iii
Propeller speed (ahead/astem)
rpm
Standard propeller mm
Marine Gear (Dia.
XpitchXnumber)
Propeller shaft dia.
X Countershaft dia. mm
Lubricat'ion system
Lube oil pan ITotal capacity e
IEffective capacity e
Cooling system
Weight
[kg]
Overall length mm
Dimensions Overall width mm
Overall height mm
Engine weight without marine
gear (dry)
kg
Lubricating oil capacity Effect/max.
.e
(Note) Rating condition: ISO - 3046/1, 1HP =;: 0.7355kW
4JH3E 4JH3BE 4JH3CE
Vertical 4-cycle water cooled diesel engine
Direct injection
Normal aspiration
4
84 X 90
1.995
36.8/3650 34.6/3650
(50/3650) (47/3650)
6.18
5.81
10.95
41.2/3800 38.2/3800
(56/3800) (52/3800)
6.65
11.4
17.7
mo· 100·
180' 180'
1 -3 -4 -2 -1
In-line type YPES-CL (with Timer)
(b.T.D.C.)
12·
220±5
Hole type
Counter-clock
wise
viewed from stern
At Flywheel side
Constant high temperature fresh water cooling
Fresh water : Centrifugal pump
Sea water :Rubber impeller
pump
Forced lubrication with trochoid pump
DC 12V,1.2kW
12V,55A (12V,
80A: option)
KM3P KM3A (
Sail Drive SD-31 can be used )
Mechanical cone clutch Mechanical cone clutch
directly on location.
(torque limiter no angle)
2.36/3.16
2.61 /3.16 2.33/3.04 2.64/3.04
1610/1203 1457/1203 1629/1249 1441/1229
--
--
Splash
0.35
0.45
0.05 0.05
--
--
[13J
{13)
849.6
563.1
623.6
223
5.3/1.1 at engine installation angle
o·
1-4
--
--
--
--
--
--
639.8
563.6
623.6
210
Printed in Japan
HINSHI-H8009

Chapter 1 General
_;;;.2;.... S~p:...e-c ... in;...ic_a_t.;..;io;...n ... s ___________________________ 3,4JH3(B)(CJE
2-3 Sales condition, Marine gear
Reduction ratio
{Marine gear model)
3.20
3.21
2.61
2.64
2.36
2.33
Primed in Japan
HINSHI-118009
(KM3P)
(KM3A)
{KM3P)
(KM3A)
(KM3P)
(KM3A)
No. of blades
3
4
3
4
3
4
Outer diameter Moment of propeller Propeller Engine
of propeller inertia
{GO
2kg-m2) maleria!s application
;;i;if,490
~0.23
3JH3(B)E
~¢,460
,;;;; ,f 470
;;;iQ,19 Bronze
~,;f440
3JH3(B)E
;;;.ef,450 4JH3(B)E
;;;i0.15
;;i;ef,425
1-5

.....
I
O'l
DETAIL OF COUPLING
SCALE 1/3
5206
273
247.S
194.1
(140.5)
1!3.2 1205
330
480
1MIXING ELBOW,
UMIXING ELBOW
j . $l_:
.--~~r.~-_cJ i
,r· BLOCKS ID#2
I ~ ~
.1 ~J
-i--------JIH - - - -+- - - --==-
0
"'
¢12_
U MIXING ELBOW ¢76
(OPTIONAL;,
MIXING ELBOW 9'76.3
ASTERN
AHEAD
BLOCKS ID#15
28.8
755.6
DIRECTION OF ROTATION
~
DETAIL OF PULLEY
SCALE 1/3
VIEW IN DIRECTION OF ARROW A
C,l
I
...
~
:::r:
c.:,
m
-
~
;;::;:
~
"
s:
C.u
"'O
s:
I»
::i.
::,
Cl)
(0
Cl)
I»
~
u)
~Q
~~
■
m
~- ~
::::i ._
:::J
(b
0~
cc
t:: :::i
CJ,
-■
....
~
:::--
:::J
::::i. .....
(1)
(b
0
C
r+
-
-■
:::J
(1)

.....
I
--.,
~
,,.
~G T 1!11
-'
·-~ .-
DETAIL OF COUPLING
SCALE 113
5205
273
194.1
1--!14M)
247.6
~- -
- 4?1)e,._ __ _
w
,ll
MIXINGJLBOW __
u-::M!XJNG ELBOW
MIXING ELB?W IP 76.3
'
28.8
A
dC:J
<o'"l-,
ft'
DETAIL OF PULLEY
SCALE
113
wA
VIEW IN DIRECTION OF ARRO

......
I
00
WATER
7NLITT26
DETAIL OF COUPLING
SCALE 1/3
563.1
315.6
247.5
194.1
1140.5)
93.2 120.5
330
480
MIXING ELBOW
UMIXING ELBOW
/12
U MIXING ELBOW i1'76
(OPTIONAL;
MIXING ELBOW¢763
ASTERN
AHEAD
6-M8A 1.25 DEPTH 16121
(INCLUDING DAMPER THICKNESS)
.d'-~~- A
dCJ
FUEL OVERFLOW 11'8
FUEL INLET ¢8
ROTATION ...,
~
Oi
r..""
q_G
3.8
DETAIL OF PULLEY
SCALE 1/3
VIEWED FROM A
c..:,
I
c..:,
t
::I:
c..:,
m
-
:E
;:.:
:::,-
;;,.::
s::
c..:,
""O
s::
ll>
:::::!:.
:::J
(D
(Q
(D
ll>
.:::!.-

0
;::~ ~
':'~
::,::,~~...J:;,c_
DETAIL OF COUPLING
SCALE 113
563.1
315.6
2475
194.1
(1405)
93.2 120.5
330
480
!,l,:MIXJNG ELBOW 4'76
(OPTIONJ\Ll
6.9
/~ilNCLUDING D~MPER THICKNESS!
··-_ dC7
,
'
00
,
~
l;l
"
3.8
DETAIL OF PULLEY
SCALE 1/3
VIEWED FROM A

.....
l
t5
MAHKSOF
PIPING
RH
$GP
STS
C1201T
-tit-
-tt---
t--
--<-
•·~ -
--
.,..
~
-
-
~~--
_,,._"
.......
-
...
--
NAME
RUBBER
HOSE
STEEL
PIPE
COPPER
PIPE
SCREW
JOINT
(UNK'IN)
RANGE
JOINT
EYEJOJNT
INSERTION
JOINT
DR!llHOLE
COOLING
FRESH
WA
lER
PIPING
COOLING
SEA
WATERPIPiNG
LUB.
OIL
PIPING
FUEL
OIL
PIPING
Note :
The following piping diagram is for the 4JH3E model. The piping diagram for the 3JH3E model is
the same with the exception that this model has 3 cylinders.
FUEL
Oil
FILTER
(CARTRIDGE
TYPEi
PRESSURE
CONTROL
VALVE
LUB
Oil
PUMP
FRESH
WATER
TEMPERATURE
SWJTCH
'P27Xl4
RH
HOT
WATER
CONNECTION
INLET
COOLING
WATER
PUMP
(FRESH
WATER)
'P28.6x!2
C120lT
NOTES
''OXl3RH
"flx
13
RH
"''"7xt3
RH
\
1.
DIMENSION
Of
STEELPIPE
:
OUTER
DIA.
XTH!CKNESS
DIMENSION
OF
RUBBER
PIPE:
INNER
DIA.
XTHICKNESS
2
FUEL
RUBBER
PIPES
ARE
SATISFIED
WITH
THE
SPECIFICATION
OF
MAN
UF
AC
TUER
(No.
KH·500·0)
(MARKED
".}
"¢7X!3
RH
1'1"7x!3
RH
FUEl
INJECTION
PUMP
164.76X0.7
STS
FUEL
HIGH
PRESSURE
PIPE
166,35xt2,
175
ST$
FUEL
INJECTION
NOZZLE
Oll.
PRESSURE
SWTCH
.
.
.
J \
I\
! \
:,--::--,/*,~\--
-
,.,_,.--
~,-
---
,.--•..--µ...-'l=C..-.\,..UI
~
\
FRESH
WATER
COOLER
LUB
OIL
INLETFIL
TEA
~\
¢
nsAx\4.3
RH
¢
jll25.4
xt4.3
RH
¢
¢25.4
xt4.3
RH
MAIN
BEARJNG
1625xt1.B
C1201T
~
~
~9
I
....
•
~~
c.:i
-c
't:,'
~
~
::;·
.,
c...
-·
O'ti
._
::c
"'C
t::,~
c.)
..... Q
m
-·
i:-..i
(b
-
:::l
~
~
-
()
(C
~
-
-
E:!
m
[ll
C
-■
Q.l
<.C
~
3
"'

Printed in Japan
IITNSHl•H8011
CHAPTER 2
INSPECTION AND SERVICING OF
BASIC ENGINE PARTS
1. Cylinder Block ·······························································2-1
1-1 Inspection of parts······················································2-1
1-2 Cleaning of oil holes···················································2·1
1-3 Colorcheckprocedure················································2·1
1-4 Replacement of cup plugs ····· ·· ···· ·· · ·· ······· ·· ······· ·· ········2-2
1-5 Cylinder bore measurement··········································2-3
2. Cylinder Head ·······························································2-4
2-1 Inspecting the cylinder head··········································2-5
2-2 Valve seat correction procedure ········ ·· ··························2-6
2-3 Intake/exhaust valves, valve guides ······························2-6
2-4 Valve springs ····························································2-8
2-5 Assembling the cylinder head ··········· ·· ······· ·· ·················2-9
2-6 Measuring top clearance ·············································2-9
2-7 Intake and exhaust valve arms ····································2-9
2-8 Adjustment of valve head clearance······························2-10
3. Piston and Piston Pins ···················································2-11
3-1 Piston ·····································································2-12
3-2 Piston pin ·······························································2-12
3-3 Piston rings ·· ·· ······· ·· ······· ·· ···························· ·· ········2-13
4. Connecting Rod ····························································2-15
4-1 Inspecting the connection rod ·························· ·· ········2-15
4-2 Crank pin bushing ········································· ·· ········2-16
4-3 Piston pin bushing ········································· ·· ······· ·2-16
4-4 Assembling piston and connecting rod···························2-17
5. Crankshaft and Main Bearing ··········································2-18
5-1 Crankshaft·······························································2-18
5-2 Main bearing ····························································2-20
6. Camshaft and Tappets ··································· ·· ··············2-21
6-1 Camshaft ·······························································2-21
6-2 Tappets ··································································2-22
7. Timing gear ··································································2-24
7-1 Inspecting the gears ················································2-24
7-2 Gear timing marks ···················································2-25
8. Flywheel and Housing ········ ·· ················ ·· ·······················2-26
8-1 Specifications of flywheel ··········································2-26
8-2 Dimensions of flywheel and mounting flange ··················2-27
8-3 Ring gear ·······························································2-28
8-4 Position of top dead center and fuel injection timing ·········2-28
8-5 Damper disc and cooling fan ·······································2-29

Chapter 2 Basic Engine
.!.l.:..;C~y~l:.:in.:,:;d:,:;e:;_r.;:;B~lo;.::c;::k _________________________ 3,4]H3(BXC)E
1. Cylinder Block
The cylinder block is a thin-skinned, (low-weight), short
skirt type with rationally placed ribs. The side walls are
wave shaped ta maximize ridigity for strength and low
noise.
Cap plug 50mm --
(camshaft hole)
Cap plug 30mm
1-1 Inspection of parts
Make a visual inspection to check for cracks an engines
that have frozen up, overturned or otherwise been sub•
jected to undue stress. Perform a color check
on any por-
tions that appear to be cracked, and replace the cylinder
block if the crack
is not repairable.
1-2 Cleaning of oil holes
Clean all oil holes, making sure that none are clogged up
and the blind plugs
do not come off.
Colar check kit
Printed in Japan
IIINSHl-ll8009
~
~
-
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Quantity
Penetrant
Oeveloner
2
Cleaner 3
2-1
Cap plug
0
'a,---cap plug 12mm
(main gallery)
1-3 Color check procedure
(1) Clean the area to be inspected.
(2) Color check kit
The color check test kit consists of
an aerosol cleaner,
penetrant and developer.
(3) Clean the area to be inspected with the cleaner.
Either spray the cleaner on directly and wipe, or wipe
the area with a cloth moistened with cleaner.
(
4) Spray an red penetrant
After cleaning, spray
an the red penetrant and allow 5
~10 minutes for penetration. Spray on more red pene•
trant if it dries before it has been able to penetrate.
(5) Spray an developer
Remove any residual penetrant an the surface after
the penetrant has penetrated, and spray an the developer.
If there are any cracks in the surface, red dots or a red
line will appear several minutes after the developer
dries.
Hald the developer
300-400mm away from the area
being inspected when spraying, making sure ta coat
the surface uniformly.
(6) Clean the surface with the cleaner.
NOTE : Without fail, read the instructions for the color
check kit before use.

Chapter 2 Basic Engine
_1._c_y_·I_in_d_e_r_B_l_oc_k _________________________ 3.4JH3(B)(C)E
1-4 Replacement of cup plugs
Step
Description
No.
1 Clean and remove grease rrom the hole into
which the cup plug is to be driven.
(Remove scale and sealing material previously
applied)
2 Remove grease from the cup plug.
3 Apply Threebond
No. 4 to !he seat surtace
where the plug
is to be driven in.
4 Insert the plug into the hole,
5 Place a driving tool on the cup plug and drive it
in using a hammer.
I
~
f+-
"""
(
-- 2~3mrn
·using the special tool, drive the cup
plug so that the edge
or the plug ls
2mm (0.0787in.) below the cylinder
surtace.
Procedure
Tool or material used
• Screw driveror saw blade
•Thinner
c----.c:
[::> "'"""" ''"''"
materiafs with a
screw driver
or saw blade.
_..L
1(
Visually check the nick around • Thinner
the plug.
Apply over the whole outside of • Threebond No. 4
the plug.
Insert the plug so thaf it sits
conectly.
Drive in the plug parallel to the • Driving tool
seating surface.
•Hammer
--
-
'tl
Q
-
3mm 100mm
mm
Plug dia. d D
<,6 12
1' 11.9~12.0 ¢,20
¢30
2-2
'P 29.9~30.0
¢,40
Printed in japan
HINSHI-H8009

Chapter 2 Basic Engine
_1._C_y_J_in_d_e_r_B_lo_c_k _________________________ 3,4111s(B)(C)E
1-5 Cylinder bore measurement
Measure the bore diameter with a cylinder gauge at the
positions shown in the figure.
Replace the cylrnder bore when the measured value
exceeds the wear limit. Measurement must be done at
least at 3 positions as shown in the figure, namely, top,
middle and bottom positions ln both directions along the
crankshaft rotation and crankshaft center lines.
Printed in Japan
HINSHI-118009
Cylinder gauge
2-3
Top position
Middle position
Bottom position
0
N
mm
Direction of
crankshaft
center line
Direction
of
crankshaft
rotation
Standard Wear limit
Cylinder bore dia. j 84.00~16 84.03
rf,84.20
Cylinder roundness
0~0.01
0.03
mm

Chapter 2 Basic Engine
_2_. C_y;....J_in_d_e_r_I_le_.a_d _________________________ S.4JHJ(B)(C)E
2. Cylinder Head
The cyllnder head is of 4-cy!inder integral construction,
mounted with 18 bolts. Special alloy stemte with superior
resistance to heat and wear
is fitted on the seats, and the
area between the valves
is cooled by a water jet.
Valve rocker arm shaft
,.oo 0
• ~de::-;
,sOei,~
e""c:3
,.ei .. ~e
sc::5
.,a .<:S
e
Cylinder head gasket
2-4
Printed in Japan
HINSHI-H8009

Chapter 2 Basic Engine
_2._C_y_J_in_d_e_r_H_e_a_d _________________________ 3,4JH3(B)(C)E
2-1 Inspecting the cylinder head
The cylinder head is subjected to very severe operating
conditions with repeated high pressure, high temperature
and cooling. Thoroughly remove all the carbon and dirt
after disassembly and carefully inspect all parts.
2- 1.1 Distortion of the combustion surface
Carefully check for cylinder head distortion as this leads to
gasket damage and compression leaks.
(1} Clean the cylinder head surface.
(2) Place a
straight-edge along each of the four sides
and each diagonal. Measure the clearance between
the straight-edge and combustion surface with a feeler
gauge.
Measurement procedure
Straightedge
n
feeler gauge
Cylinder head distortion
mm
Standard Wear limit
0.05
or less 0.15
2-1.2 Checking for cracks in the combustion surface
Remove the fuel injection nozzle, intake and exhaust
valve and clean the combustion surface. Check for discol-
oration or distortion and conduct a color check test to
check for any cracks.
10-=...J
!@,
__,.c:;,., -
•'
~
Printed in Japan
HINSHI-H8009
2-5
2-1 .3 Checking the intake and exhaust valve seats
Check the surface and width of the valve seats.
If they are too wide, or if the surfaces are rough, correct to
the following standards:
Seat angle
Seat width
Intake
Exhaust
Intake valve seal
Exhaust valve seat
(3)
2:
(I)
>
w
::::J
~
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><
w
Intake 120·
Exhaust
90'
Standard Wear limit
1.07 ~1.24
1.74
1.24~1,45
1.94
€,Ly,,
120·
Standard dimension
.,,
0
~
Q,)
>
<U
>
Q,)
c.:
II'.)
:s
<f- ¢35
120·
C,
0