Westerbeke W-46 User manual

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SERVICE MANUAL
W-46 MARINE DIESEL ENGINE
..
AND
15/12: BTD MARINE DIESEL GENERATOR
SINGLE AND THREE PHASE
PUBLICATION. N0.34907
REVISION. 2
OCTOBER. 2017
l~ rWESTERBEKE.
~ WESTERBEKE CORPORATION • 150 JOHN HANCOCK ROAD
.J MYLES STANDISH INDUSTRIAL PARK• TAUNTONMA 02780
WEBSITE: WWW.WESTERBEKE.COM
.. ,

A wARNING
Exhaust gasses contain Carbon Monoxide, an odorless and
colorless gas. Carbon Monoxide is poisonous and can cause
unconsciousness and death. Symptoms of Carbon Monoxide
exposure can include:
•Dizziness
• Throbbing in Temples
•Nausea
•Headache
• Muscular Twitching
• Vomiting
• Weakness and Sleepiness
• Inability to Think Coherently
IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS,
GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist,
seek medical attention. Shut down the unit and do not restart
until
it has been inspected and repaired.
A WARNING DECAL is provided by
WESTERBEKE and should be fixed to a
bulkhead near your engine or generator.
WESTERBEKE also recommends installing
CARBON MONOXIDE DETECTORS in the
living/sleeping quarters of your vessel.
They are inexpensive and easily
obtainable at your local marine store.
CALIFORNIA
PROPOSITION 65 WARNING
Diesel engine exhaust and some
of its constituents are known to
the State of California to cause
cancer, birth defects, and other
reproductive harm.

TABLE OF CONTENTS
INTRODUCTION ............................................... ...... 2
Serial Numbcr................................................2
TEmNG FOR OVERHAUl .................................. .... 3
Compression Test ..........................................3
Compression Pressure ...................................3
ENGINE TROUBLESHOOTING (Pages 4-7) .............. 4
ENGINE DISASSEMBLY (Pages 8-15) .................... 8
Fuel lnjectiun Pump Removal.......................8
Order ofEngine Disassembly .....................10
INSPECTION AID REPAIR (Pages 16-35) ........... 16
ENGINE ASSEMBLY (Pages 36-47) ..................... 36
Fuel Injection Pump (Pages 48-50) ............. 48
LUBRICATION SYSTEM (Pages 51-54) ................ 51
COOUNG SYSTEM (Pages 55-60) ....................... 55
FUEL SYSTEM (Pages 61-68) ............................. 61
TIGHTENING TORQUE .......................................... 69
STARTER MOTOR ........................................ ........ 70
ALTERNATOR (Pages 73-77} ............................... 73
TRAISMISSIOIS .................. ............................... 78
Borg \Vamer.................................................78
Walter V~Drivc ............................................. 81
ZF ...............................................................83
THE BT GENERATOR (Pages 85-1 00) .................. 85
Troubleshooting, Testing & Diagrarns ........85
ENGINE WIRING DIAGRAMS (Pages 101-105) .. 101
ENGINE SPECIFICATIONS (Pages 106- 109) .. .... 106
GENERATOR SPECIFICATIONS .......................... 110

INTRODUCTION
SERIAL NUMBER LOCATION
NOTES, CAUTIONS AND WARNINGS
As this manual takes you through the disassembly, inspection
and assembly procedure ofyour engine/generator, critical
information will be highlighted by NO'IES, CAUTIONS,
and WARNINGS. An explanation follows:
NOTE: An operating procedure essential to note.
A CAUTION: Procedures, which if not strictly
observed, can result in the damage or destruction of
your engine/generator. ·
A WARNING: Procedures, which If not properly
followed, can result in personal injury or loss of life.
ORDERING PARTS
Whe~ever replacement parts are needed, always provide the
generator model number, engine serial number, and generator
serial number as they appear on the silver and black
name-plate located on the generator end. You must provide
us with this information so we may properly identify
your engine/generator. In addition, include a complete part
description and part number for each part needed (see
the separately furnished Parts List). Also insist upon
WESTERBEKE packaged parts because will fit or generic
parts are frequently not made to the same specifications
as original equipment.
2
RAW WATER COOLING CIRCUIT
Siphon-Break
For installations where the water injected exhaust elbow is
close to or will bebelow the vessels waterline, provisions
must be made to install a siphon-break in the raw water
supply hose to the water injected exhaust elbow. The siphon-
break provides an air vent in the raw water cooling system to
prevent taw water from filling the exhaust system and the
engine's cylinders when the engine is shutdown.
If you have any doubt about the position ofthe water-
injected exhaust elbow relative to the vessels waterline under
the vessels various operating conditions, install a siphon-
break. This precaution is necessary to protect your engine.
The siphon-break must be installed in the highest point ofa
hose
.that is looped a minimum of 20 ioches (51 em) above
the vessels waterline. This siphon-break mustalways be
above the waterline during all angles of vessel operation to
prevent siphoning. .
NOTE: A siphon-break requires periodic inspection and
cleaning to ensure proper operation. Failure..J.o properly
· maintain a siphon-break can result in catastrophic engine
dmnage. Consult the siphon-break 11U11J,Ufacturerf6r proper
maintenance.
SIPHON-BREAK WITH STAINLESS
LOOP FOR 1" HOSE
PART N0.044010
ENGINE OVERHAUL
The following sections contain detailed information
relating
to the proper operation characteristics of the major
components and systems of the engine. Included are
disassembly, inspection and reassembly instructions for the
guidance ofsuitable equipped and staffed marine engine
service and rebuilding facilities. The necessary procedures
should be taken only by such facilities.
Additional detailed information
and specifications are pro-
vided in other sections of this manual, covering the
generator, alternator, starter motor, engine adjustments,
coolirtg pumps, etc. ·

·TESTING FOR OVERHAUL
HOW TO DETERMINE ENGINE OVERHAUL PERIOD
CaQse of Low Compression
Generally, the time at which an engine should be overhauled
is determined by various conditions such as lowered engine .
power output, decreased compression pressure, and increased
fuel and oil consumption. The lowered engine power output
is not necessarily due to trouble with the engine itself, but is
sometimes caused by injector nozzle wear or injection pump
wear. The decrease in compression pressure is caused by
many factors. It is, therefore, necessary to determine a cause
or causes on the basis ofdata produced by periodic
inspection and maintenance. Oil analysis on a seasonal basis
is a good means ofmonitoring engine internal wear. When
caused by worn cylinders or pistonrings, the following.
symptoms will occur: ·
1 Low engine .,;ower output
2 Increased fuel consumption
·3 Iitcreased oU consumption
4 Hard engine starting
5 Noisy engine operation
These symptoms often appear together. Symptoms Zand 4
can result also from excessive fuel injection, improper injec-
tion timing, and wear of the injectors. They are caused also
by defective electrical devices such as the battery, alternator,
starter and glow plugs. Therefore it is desirable to judge the
optimum engine overhaul time by the ·Jowered compressio!l
pressure caused by worn cylinders and pistons plus increased
oil consumption. Satisfactory combustion is obtained only
under sufficient compression pressure. If an engine lacks
compression pressure, incomplete combustion of fuel will
take place even if other 'parts ofthe engine are operating
properly. To determine the period of engine overhaul, it is
imporbplt.to measure the engine compression pressure regu-
larly. At the sl\!!le time, the engine speed at which the mea-
. surement of compression pressure is made should be checked
because the compression pressure varies with engine rpm.
The engine rpm ca:n· be m~ured at the front end ofthe
crankshaft.
NOTE: In case of severe vibrations and detonation noise, the
cause may be}'u£1 ir{jector problems, see FUEL lNJECI'ORS.
Pool fuel quality, contaminates and loss of positive fuel
prnssure to the injection pump will result in injector faults.
NOTE: Make certain the engines valve clearances are
properly adjusted. An _incorrect valve clearance can cause
symptons that might, incorrectly, suggest an engine overhaul
(cylinder misfire, white smoke, noise, etc).
OVERHAUL CONDITIONS
Compression pressure tends to increase a little in a new
engine until piston rings and valve seats have been broken in.
Thereafter, itdecreases gradually with the progress of wear
ofthese parts.
When decrease ofcompression pressure reaches the repair
limit, the engine must be overhauled.
COMPRESSI_ON TEST
When testing compression the Control Panel (generators),
or the Instrument Panel (propulsion engine ) can be by-passed
by connecting an electrical jumper directly to the .starter as shown
. in the illustration below. A jumper can easRy be fabricated using
wires and a pushbutton.
. DISASSEMBLY
COMPRESSION PRESSURE:
440 PSI/31kg-cm (normal)
355PSI/ 25kg-cm ( limit)
NOTE: Befo'f! disassembly aiu:Lcleaning, ca~lly check
for defects which· cannot be found after disassembly and
cleaning. · · ·
• All disassembled parts should be carefullY._ arranged in
order of reassembly. Mark orlabel the partS It& needed
to insU.re proper mating and reassembly' in the proper·
directions and positions.
• It:the disassembly procedure is complex requiring many
parts to be' disassembled, the parts snould be disassembled
in a way that will allow them to be efficiently reassembled
without any change in the engine's external appearance or
its perfonnance. ·
• Do not remove or disassemble the parts that require no
disassembly.
• Carefully inspect each part after its removal for damage,
deformation, and otherproblems.
• Carefully check gaskets, packings and oil seals, even if
checking is not specified. Replace with new ones if defective.
• Be careful not to damage the disassembled parts. Keep the
parts clean.
• Use proper tools. Apply oil when necessary. Ta:ke special
care· to keep the fuel system parts free from the intrusion
ofdust and dirt. ·
ASSEMBLY
1. Wash all p~. exceptfor oil seals, 0-rings, rubber sheets,
etc., with cleaning solvent and dry them with pressure air.
Z. Always use tools that are in good condition ahd be sure·
you understand how to use them before perfonning any
job.
3.
Use only good quality lubricants. Be sure to apply a coat
ofoil, grease or sealant to parts as specified ..
4. Be sure to use a torque wrench to tighten parts for which
torques are specified.
·Engines&Generators
3

ENGINE TROUBLESHOOTING
The following troubleshooting chart describes certain
problems relating to engine service, the probable causes of
these problems, and the recommendations to overcome
these problems.This chart may be
of assistance in
determining the need for an engine overhaul.
PROBLEM
PROBABLE CAUSE
HARD STARTING
LOW CRANKING SPEED
1. Engine oil viscosity too high.
2. Run-down battery.
3. Worn battery.
4. Battery terminals loosely connected.
5. Defective starter.
DEFECTIVE INJECTION SYSTEM
1. Air trapped in fuel passage.
2. Clogged fuel filter.
3. Low injeCtion pressure.
4. Inadequate spray.
5. Injection pump delivering insufficient fuel.
6. Injection too early.
MAIN ENGINE TROUBLES
1. Low compression.
a. Incorrect valve clearance.
'
b. Inadequate contact of valve seat.
c. Valve stem seized.
d. Broken valve spring.
NOTE: The engine's electrical system is protected by a 20-
ampere manual reset circuit breaker. The preheat solenoid is
mounted on the same bracket.
VERIFICATION/REMEDY
1. Replace engine oil with less viscous oil.
2. Recharge battery.
3. Replace battery.
4. Clean terminals and correct cables.
5. Repair or replace starter.
1. Bleed air from fuel system.
2. Clean or replace filter.
3. Adjust injection pressure.
4. Clean or replace nozzle.
5. Repair or replace injection pump.
6. Adjust injection timing.
a. Adjust valve clearance.
b. Lap valve.
c. Replace valve and valve guide.
d. Replace valve spring.
e. Compression leaks through cylinder head gask.et. e. Replace gasket.
f. Piston ring seized.
f. Replace piston and piston ring.
g. Worn piston ring and cylinder.
g. Overhaul engine.
2. Burnt glow plug.
2. Replace glow plug.
3. Faulty glow plug operation.
3. Check preheat circuit.
4. Incorrect governor lever position.
4. Set lever to starting position.
5. Governor spring out of POSITION
5. Correct spring
LOW OUTPUT LOW COMPRESSION
See HARD STARTING
INJECTION SYSTEM OUT OF ADJUSTMENT
1. Incorrect injection timing.
1. Adjust injection timing.
2. Insufficient injection.
2. Repair or replace injection pump.
3. Low injection pressure.
3. Check injection nozzle and adjust pressure.
INSUFFICIENT FUEL
1. Air trapped in fuel system.
1. Check and retighten connector.
2. Clogged filter.
2. Clean or replace filter.
3. Contaminated fuel tank.
3. Clean tank.
INSUFFICIENT INTAKE AIR
1. Clogged air cleaner.
1. Clean or replace air cleaner.
(continued)
4

ENGINE TROUBLESHOOTING
PROBLEM PROBABLE CAUSE
VERIFICATION/REMEDY
LOW OUTPUT (cont •• } OVERHEATING
1. Low coolant level.
1. Add coolant.
2. loose V-belt.
2. Adjust or replace V"belt.
3. Incorrect injection timing.
3. Adjust injection timing.
4. Low engine oil level.
6. Add engine oil.
EXCESSIVE OIL
OIL LEAKAGE
CONSUMPTION 1. Defective oil seals.
1. Replace oil seals.
2. Broken gear case gasket.
2. Replace gasket.
3. loose gear case attaching bolts. 3. Retighten bolts.
4. Loose drain plug. 4. Retighten plug.
5. Broken rocker ccwer gasket.· 5. Replace gasket.
6. Loose rocker cover attaching bolts.
6. Retighten attaching bolts.
OIL LEVEL RISING
1. leaking injection pump.
1. Repair pump plungers.
2. Bent or twisted connecting rod.
2. Replace connecting rod.
3. Worn piston ring.
3. Replace ring.
4. Worn piston or cylinder.
4. Replace piston and rebore cylinder.
OIL LEVEL FALLING
1. Defective stem seal. 1. Replace stem seal.
2. Worn valve and valve guide.
4. Replace a valve and valve guide.
EXCESSIVE FUEL
l
ENGINE BODY TROUBLES
CONSUMPTION
1. Noisy knocking.
1. See KNOCKING.
2. Smoky exhaust.
2. See SMOKY EXHAUST.
3. Moving parts nearly seized or excessively worn. c.
3. Repair or replace.
4. Poor compression.
4. See LOW COMPRESSION; HARD STARTING.
5. Improper valve timing.
5. Adjust.
6. lm~roper valve clearance.
6. Adjust.
INSUFACIENT INTAKE AIR
1. AirJntake obstructed.
1. Remove obstruction.
NOZZLE TROUBLES
1. Seized nozzle.
1. Replace.
2. Worn nozzle.
2. Replace.
IMPROPER FUEL
Replace with proper fuel (Cetane #45 or better).
-
FUEL LEAKS
Find fuel leaks.
SMOKY EXHAUST WHITISH OR PURPLISH
. 1. ExcessiVe engine oil.
1. Correct oil level.
2. Excessive rise of oil into combustion chamber.
a. Poor piston contact.
a. Check.
b. Seized piston ring.
b. Replace or clean.
c. Excessive piston-to-cylinder clearance.
c. Replace or correct.
(continued)
5

ENGINE TROUBLESHOOTING
PROBLEM
I
PROBABLE CAUSE
VERIFICATION/REMEDY
SMOKY EXHAUST (cont.
1
WHITISH OR PURPLISH (cont.
d. Worn valve stem and valve guide.
d. Replace.
e. Low engine oil viscosity.
e. Replace.
f. Excessive oil pressure.
f. Correct.
3. Injection timing is too late. 3. Adjust.
4. Insufficient compression. 4. See LOW COMPRESSION; HARD STARTING.
BLACKISH OR DARK GRAYISH
1. Engine body trouble.s.
a. Poor compression.
a. See LOW COMPRESSION; HARD STARTING.
b. Improper valve clearance.
b. Adjust.
2. Insufficient intake air (air cleaner clogged). 2. Clean air cleaner.
3. Improper fuel. 3. Replace with proper fuel.
ABNORMAL SOUND
CRANKSHAFT AND MAIN BEARING
OR NOISE 1. Badly worn bearing.
1. Replace bearing and grind crankshaft.
2. Badly .worn crankshaft.
2. Grind crankshaft.
3. Melted bearing.
3. Replace bearing and check lubrication system.
·CONNECTING ROD AND CONNECTING ROD BEARING
1. Worn connecting rod big end bearing.
1. Replace bearing.
2. Worn crankpin.
2. Grind crankshaft.
3. Bent connecting rod. 3. Correct bend or replace.
PISTON, PISTON PIN, AND PISTON RING
1. Worn cylinder. 1. Rebore cylinder to oversize and replace piston.
2. Worn piston pin. 2. Replace piston.
3. Piston seized.
3. Replace piston and rebore cylinder.
4. Piston seized and ring worn or damaged. 4. Replace piston and rings.
VALVE MECHANISM
1. Worn camshaft. 1. Replace.
2. Excessive valve clearance.
2. Adjust.
3. Wor.n timing gear. 3. Replace.
4. Worn fan pulley bearing.
4. Replace.
ROUGH OPERATION INJECTION PUMP SYSTEM
1. Uneven injection.
1. Adjust injection or replace parts.
2. Control rack malfunctioning.
2. Disassemble, check and correct injection pump.
3. Worn delivery valve. 3. Replace.
4. Inadequate injection nozzle spray.
. 4. Replace injection nozzle.
GOVERNING SYSTEM
1. Governor lever malfunctioning.
1. Check governor shaft and correct operation.
2. Fatigued governor spring.
2. Replace.
(continued)
6

ENGINE TROUBLESHOOTING
PROBLEM PROBABLE CAUSE
VERIFICATION/REMEDY
KNOCKING ENGINE KNOCKS WITHOUT MUCH SMOKE
1. Main engine troubles.
a. Overheated cylinder.
a. See OVERHEATING; LOW OUTPUT.
b. Carbon deposits in cylinder.
b. Clean.
2. Too early injection timing.
2. Correct.
3. Too high injection pressure.
3. Correct.
4. Improper fuel.
4. Replace with proper fuel.
KNOCKING WITH DARK SMOKE
1. Poor compression.
1. See LOW COMPRESSION; HARD STARTING.
2. Injection pump malfunctioning.
a. Worn plunger.
a. Replace.
b. Pinion is not in mesh with control rack.
b. Correct.
c. Broken delivery valve spring.
c.' Replace.
d. Worn delivery valve seat.
d. Replace.
3. Improper nozzle.
a. Poor spray.
a. Clean or replace nozzle.
b. Poor chattering. b. Repair or niplace nozzle. ·
c. After-injection drip.
c. Repair or replace nozzle.
d. Nozzle needle valve seized.
d. Replace.
INTERMITIENl
1. Fuel filter clogged. 1. Clean or replace.
EXHAUST SOUND
2. Fuel pipe sucks air.
2. Retighten pipe joints or ~eplace pipe.
3. Water mixed in fuel
-
3. Replace fuel.
OVERHEATING
1. V-belt slackening or slippery with oil. 1. Adjust, replace or clean.
2. Damaged water pump. 2. Replace.
3. Lack of coolant. 3. Add.
4. Low oil level or poor oil quality. 4. Add or change.
5. Knocking. 5. See KNOCKING.
6. Moving parts seized or damaged. 6. Replace.
7. Defective thermostat.
7. Replace.
LOW OIL PRESSURE
1. Worn Bearings. 1. Engine overhaul replace bearings.
2. Relief valvl! malfunction. 2. Overhaul oil pump.
3. Clogged oil cooler. 3. Repair.
4. Diesel dilution of the oil. 4. Injection pump repair.
7

ENGINE DISASSEMBLY
DESCRIPTION
Switch offthe batteries and disconnect the battery cables
from the engine and tape over the terminals.
Drain orpump out all the engine oil and drain the coolant
from the engine and engine hoses.
Unplug the instrumental panel wiring harness. Drain the
transmission fluid and the transmission oil cooler hoses.
Detach the oil cooler hoses and unbolt the transmission from
the engine.
NOTE: Label any lines, hoses orcables as you separate them.
• Clean the exterior of the engine of any deposits of dirt
and oil.
• Be careful not to damage the disassembled parts.
• Mount the engine on a suitable engine standfor disassembly.
• Pay attention to marks on assemblies, components and
parts for their positions or directions. Put on marks,
if
necessary, to aid assembly.
• Carefully check each part or component for any sign of
faulty condition during removal or cleaning. The part will
tell you how it acted
or what was abnormal about it more
accurately during removal
or cleaning.
i~~~
~c~
~ ,, .
.. •)
. HEAT EXCHANGER DRAINS
TRANSMISSIONS
The transmission section of this manual contains general
information and speciffCBtions for the transmissions used
in the W-46 engine.
If the transmission is not being rebuilt, it should be inspected ·
cleaned and repainted. The oH cooler should be nushed out
and pressure tested and the cooling hoses replaced. Inspect
and lubricate the gear shift linkage and the propeller shaft
coupling. Ghange the transmissirJn fluid.
To rebuild the transmission contactyour WESTERBEKE
dealer or an authorized transmission setvlce center.
HSW HURTH TRANSMISSION
HYDRAULIC
TRANSMISSION'S
BOLT DIRECTLY TO THE
BELL HOUSING AND
!HAVE A SEPARATE
Oil COOLER ' .
8
DISASSEMBLY
1. Remove the engine oil hose connections.
2. Remove
the engine heat exchanger. If possible, leave
one end
of each hose connected to the part being
removed.
3. Remove
the engine back plate.
4. Remove
the startmotor, drive belt and the alternator.
Label the wires and cables.
5. Remove
the engine mounted raw water pump,
adapter mounting plate, and drive from the front
cover. The drive is removed by turning in a counter
clockwise direction. See RAW
WATER PUMP for parts
breakdown.
6. Remove
the coolant recirculating pump See COOlANT.
RECIRCULATING PUMP for parts breakdown.
7. Remove
the air intake silencer and the intake
manifold.
e. Remove the alternator, drive belt, support brackets and
adjusting strap.
f. Remove the engine mounted raw water pump and its
connecting hoses. Refer to the raw water pump in this
manual.
e. Remove the flywheel. Loosen the front crankshaft
pulley nut before removing the flywheel.
WHEN REMOVING
THE MOUNnNG BOLTS
LOCK THE FLYWHEEL
. WITH A RING GEAR .·
BREAK TOOL
INSPECT THE DAMPER
PlATE FoR WEAR AND
BROKEN SPRINGS
FLYWHEEL BOLT PAmRN
TAB WASHER
ntANSMISSION
DAMPER PLATE

ENGINE DISASSEMBLY
8. With the hoses disconnected, remove the thermostat
housing and housing gasket, leaving the temperature
sender in place.
9. Remove
the coolantcirculating pump. Refer to
COOLANTPUMPASSEMBL~
10. Remove the airintakesilencer and the intake manifold.
11. Remove the oil filter and the mounting bracket from
the engine block.
12.Unbolt
the elbows and remove the exhaust manifold
in its entirety.
Remove the exhaust manifold/expansion tank in its
entirety. Disassemble separately, clean
aU surfaces, install
new gaskets when assembling. Use good quality gasket
cement.
NOTE: Early versions were an assembly, later versions are a
cast
unit. (Cast units are only available today).
14.Remove the engine mounted fuel filter with electric
fuel lift pump and related lines.
NOTE: The positions of the sealing washers that attachfuel lines
to the fuel filter; the injection pump andthe electricfuel pump.
15.Remove the fuel injection pump.
Disconnect the fuel injection pipes and fuel leak-offpipe
from the fuel injection pump and nozzles.
NOTE: Put plugs orcaps on the openings of the injection pump
and nozzle connectors. Golftees work well as plugs.
16.Remove the fuel injection nozzles. Loosen the fuel
injection nozzles with a wrench. Remove the nozzles and
gaskets from the cylinder head. ·
Scribe mating marks on the pump body and the timing gear
case before removing.
FUEL INJECTION PUMP REMOVAL
Early model injection pumps (DTAJ394-2F4-90) had tapered
drive shafts, each with a woodruffkey that
fits into the
injection pump drive gear and was held in place in the drive
gear by a threaded tang used to drive the raw water pump.
1. Remove drive tang locking plate and unscrew drive
tang.
2. Manually rotate engine to position keyway in injection
pump drive gear/shaft at 12:00. This is important so that
when the injection pump is removed, the woodruff key
will not drop down into the front cover.
3. Remove the fuel supply and return line from the
injection pump.
4. Loosen the three bolts holding the injection pump to
the front cover plate.
NOTE: Inner hold-down boltfor injection~ump is removed with
a JOmm, flexible, 114 inch drive socket.
5. Place a soft metal drift punch against the threaded
driveshaft end of the injection pump _protruding
through the drive gear. With a hammer, give the drift
punch a sharp blow. The should dislod~ tbe pump from
the drive gear.
6. Remove
the injection pump hold-down bolts and
carefully so as not to drop the drive shaft woodruff
key
into the cover and withdraw. the injection pump.
NOTE: Although the drive gear will appear very loose in its
position, it will not change mesh with its drive idle gear.
Later ModelsDPAJ3942F580 OR 581 ,
Later style injection pumps each have a splined drive shaft
with a master spline. The drive gear has a dash mark on the
front indicating which splines must engage the master spline
on the drive shaft, ensuring the injection pump is in the
~orrect timing sequence with the engine.
1. Remove
the three bolts that hold the injection pump
onto the front cover plate and remove the pump from
the engine.
NOTE: When reinstalling the injection pump, the drive tang plate
bolted to the front of the drive gear must be removed to expose
the dash mark that indicates the splines which mate with the
master spline on the injection pump drive shaft when
reinstalling the shaft in the drive gear.
2. Removal of the fuel injectors.
a. Remove the fuel return line from the top of the
injectors by removing the four 2Smm attaching nuts.
NOTE: There are sealing washers between the injector return
banjos and the injectors, these should be replace on reassembly.
b. With a 30mm deep socket unscrew the injectors from
the cylinder head.
c. Remove the copper injectorsealing washers from the
head once the injectors are removed.These sealing
washers should be replaced upon reassembly.
d. Put the injectors aside for cleaning and rebuilding in
shop or by an authorized CAV /BOSH Injection Repair
Shop.
~ WESTERBEKE
9

ENGINE DISASSEMBLY
Disassemble in the following order:
1. Remove cylinder head rocker
cover.
2. Remove the rocker shaft
assembly as follows:
a. Loosen and remove union nut.
(1)
b. Loosen
bolts
( 3) •
and remove
(2) and long
short
bolts
c. Remove rocker shaft assembly
( 4) •
d. Remove oil pipe (5) and a-
rings (2 pes-to be replaced
with new ones).
e. Remove valve push rods and
valve caps.
3. Remove the cylinder
assembly as follows:
a. Loosen cylinder head
in reverse order
tightening and remove.
head
bolts
of
12
4 6
0 0
14
@J
16
8 7
0 0
0
17
15
5 3
0 0
13
@)
11
0
9
b. Remove the cylinder head and
gasket.
Cylinder Head Bolt Tightening Sequence
4. Remove the oil pan and oil pump
assembly as follows:
a. Loosen and remove attaching
bolts and remove oil pan and
gasket.
b. Loosen and remove
bolts and remove
assembly.
attaching
oil pump
Eng1'nes & Generators
10

ENGINE DISASSEMBLY
5. Removal of front gear train.
a. Remove
pulley
pulley.
front crankshaft
retaining nut and
b. Remove timing gear cover.
(Early models: Remove injec-
tion pump drive gear with
cover. )
c. Remove idler gear retaining
bolt ( 1) ,
thrust plate (2),
idle gear (3), and bushing.
d. Remove camshaft
nut (4), thrust
gear (5).
retaining
plate and
6. Remove the camshaft assembly as
follows:
7.
a. Position engine block so
that the cylinder head
mounting surface is down.
b. Carefully withdraw the
camshaft (1) from the engine
block.
c. Remove all push rod solid
lifters from engine block.
Remove the
injection
follows:
front plate
pump assembly
and
as
a. Loosen attaching bolts (1).
b. Remove front plate.
c. Late models: injection pump
drive gear is retained on
bearing on front plate; use
suitable puller to remove.
Enginds & Generators
11

ENGINE DISASSEMBLY
8. Remove the flywheel and back
plate.
9.
Remove
the
connecting rod
bearing
caps and
bearings
(lower
shells) by loosening
and
removing the
attaching
bolts.
Keep each
cap
and
bearing
with respective
rod.
10. Remove the main bearing caps by loosen-
ing and removing the attaching bolts.
11. Remove the crankshaft.
a. Withdraw each rod and piston as-
sembly from the bottom ofthe block.
b. Loosely replace the bearing and rod
caps. Make sure that each bearing
and rod cap is repl1:1ced in the exact
location from which it was originally
removed. Also make sure that the
caps are not turned 180° when
replaced. ·
Engines & Generators
12

~NGINE DISASSEMBLY
12. Remove the main bearing shells.
13. Disassembly piston and con-
necting rod as follows:
a. Remove compression rings (1)
and oil ring by using piston
ring tool (A).
b. Remove oil scraper expander
spring. ( 2)
c. Remove snap ring (3) by
using snap ring tool (B).
d. Remove piston pin (4) by
using drift punch (C).
e. Remove piston
and connecting
(upper) •
pin bushing
rod bearing
(NOTE: Heating the piston
by resting the piston crown
down on an electric hot
plate will allow for easier
removal of the piston pin.)
Engines & Generators
13
/ .

ENGINE DISASSEMBLY
14. Disassemble the rocker shaft
assembly as follows:
15.
a. Remove snap rings (1) on
both ends of each rocker
shaft.
b.
Remove rocker
assembly.
c.
Remove
rocker shaft
bracket
( 2) •
d.
Remove rocker
assembly~ ( 3)
e.
Remove
rocker
shaft
spring
( 4) ,
Disassemble the cylinder
head
as follows:
a. Remove glow plugs.
DOWNTO.F
f. Remove valve cotters (8).
(depress valve spring by
valve lifter.)
g. Remove retainer -(9).
h. Remove valve spring (10).
i. Take out valve (11).
j. Remove valve guide (12) from
cylinder head (13) by using
remover (A).
/
Valve guide
0.5C
~c
remover
.\
--
)8
·-t 124
~~-
30
-~
158
188
~
(Dimensiops in rom)
MATERIAL S53 C. ·
Engines & Generators
14
A
12
13

INSPECTION/REPAIR
CYLINDER HEAD
1. Inspection
Check the gasketed sur face of
the cylinder head for flatness
by using a straightedge and
thickness gauge as in the case
of checking the crankcase sur-
faces. :Refer to Crankcase.
check is to be
precombustion
removed.
This
made with the
chamber jets
use a surface grinder to reface
the cylinder head, as
necessary, to the specified
flatness.
Specifications
Unit: mm (in.)
Item
Warpage of gasketed
surface
of cylinder
head
2. Precombustion
Replacement
Standard Repair limit·
0.05,max 0.2
(0.0020) (0.008)
Chamber
Jet
Do not remove the precombustion
chamber jets unless their
replacement is necessary. To
remove the jet (if cracks are
noted in it, or if head must be
machined to specifications)
ease it out by driving with a
flat-faced drift pin inserted
through the glow plug hole, as
shown.
Before installing the jet, wash
the precombustion chamber
cavity clean, and drive the jet
into position, with its orifice
pointing to the center of the
cylinder. Calk one portion
with a punch.
A-Intake port
B-Exhaust port
C-Jet
D-Caulking position
I I
D E
Checking cylinder head gasketed surface
for flatness
Removing precombustion chamber jet
A B
Etjgifles & Generators
15

INSPECTION/REPAIR
Valve Guides and Valve Seats
1. Check each valve for carboning,
burning, wear or other defects
on the head: also check cap end
and stem for cracks. Replace
the valve if damaged.
2.
Valve guide ~
remove~
.~.sc
it -
. .
II
~-
30
-~
158
188
(Dimensions in rnrn)
Material: S53C
;,c
·-' 12•
Check each valve guide for
wear. Remember, the guide wears
more rapidly at the ends.
Measure the inside diameter of
the guide at each end and at
the middle from both direc-
tions. Measure the outside
diameter of each valve stem.
If the measurement exceeds the
repair limit given in the table
below, replace the valve guide.
Valve guide removal tool wear on valve guide
3.
Valve face and valve seat.
Check valve face and valve seat for wear and contact.
valve face is worn excessively, reface it by using
refacer. To reface the valve, proceed as follows:
Specifications Unit·
mm (in)
.
Item Standard Service
limit
Clearance Intake 0.055
-0.085
0.15
of valve
(0.00217-0.00335) (0.0059}
stem in
O.o?0-0.100 0.20
valve guide Exhaust (0.00276
-0.00394)
(0.0079)
Valve guide
18 ±0.3
length out- (0.709 ±0.012)
side hole
8-0.045
-0.060
-0.1
Intake
(0315 -0.00177)
(-0.004)
Valve stem . -0.00236
diameter
-8-0.060
Exhaust
-0.080
-0.15
(0 315 -0.00236)
(-0.0059)
. -0.00315
Specifications
Item Nominal Sti!ndard Repair Service limit
value limit
Angle . 30°
Sinkage ±0.2
1.3
Valve 0.8 (0.031) (±0.008) (0.051)
seat
Width 1.4 (0.055) ±0.14 1.6
(±0.0055) (0.063)
±0.1
Reface up to
angle
Valve margin 1.7 (0.067) 1.2
(±0.004) {0.047)
Engines & Generators
16
If the
a valve
Unit: mm (in.)
margin

valve Refacer
INSPECTION/REPAIR
·a. Set the valve refacer to an
angle of 45 degrees.
b. When grinding the valve,
remove the least amount of
material to properly reface
the valve and, if the margin
is less than 1.2 nun (0.047
in.), replace the valve.
Valve seat cutter.
Repair an excessively worn
valve seat by using a valve
gtinder or valve seat
cutter.
c. When using a valve seat
cutter, carefully apply a
uniform pressure to the
valve seat to prevent uneven
cutting. After cutting,
reface the seat by rotating
the cutter with No.400 sand-
paper placed between the
cutter and seat.
d. If valve seat width is over-
cut, repair it using a
30 degree cutter. If valve
seat width exceeds 1.6 rom
(0.063 in.) dtie to wear,
replace the seat. Also
replace the seat when valve
sinkage exceeds 1.3 mm
(0.051 in.).
valve Seat Installation
Installing 1
intake valve
inserts
3
Installing 4
exhaust
valve inserts
Exhaust
5
Intake
(exhause)
(intake)
head
l-Caultking/ body
2-Valve insert
3-Cylinder head
4-Valve guide
5-Caulking ring
intake valve
insert caulking
tool
Heat cylinder head to a temperature of 80"C to lOO•C {176"F to 212"F),
and cool the valve seat sufficiently in ether or alcohol containing
dry ice. Valve seat may be cooled in liquid nitrogen.
P.~;:ess the valve seat into cylinder head and leave the head and seat
until they cool down to room temperature.
Specifications Unit:
mm (in.)
A 8 c 0
33 +0.02 41+0.025 7.8 ±0.1
2.8 ±0.1
Valve seat 0 0 .
dimensions (1.30 +g.0008) (1.61+g.00098) (0.307 ± 0.004) (0.11 ±0.004)
...
17

INSPECTION/REPAIR
Valve Springs
Inspect each spring for cracks, and check it for squareness, free
length and as-installed length against these specifications.
valve spring tester
90"test a11gle
swface ge~ge
plate
SPECIFICATIONS
Item
Standard
Valve Spring Free Length
48.85
(outer) (1.9232)
Valve Spring Free Length 40.90
(inner) (1.60)
Valve Spring Squareness 0.4/25
(0.016/0.98)
max
Load compress spring to 19 ± 1
initial
working length (41.9 ± 2.21)
43 mm (1.69 in)
kg(lb)
·-·-·--··-·-··--
Unit: mm (in)
Repair
Limit
47.6
(1.874)
39.65
(1.55)
15
(33.08)
Engines & Generators
18