Universal M3-20B User manual

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SERVICE MANUAL
Univarsal
MARINE DIESEL ENGINE
M3·20B
PUBLICATION NO. 200562
1st Edition/July 2001
WESTERBEKE CORPORATION. MYLES STANDISH INDUSTRIAL PARK
150 JOHN HANCOCKROAD, TAUNTON, MA 02780-7319 U.S.A.
TEL: [phone]· FAX: [phone]· WEBSITE:
www.WESTERBEKECOM
~~~~
IlIMMA Member National Marine Manufacturers Association
.,.,..,

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.
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
• Nausea
• Headache
• Throbbing in Temples
• 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.
This WARNING DECAL is provided by
UNIVERSAL and should be fixed to a
bulkhead near your engine or generator.
UNIVERSAL 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.

SAFETY INSTRUCTIONS
INTRODUCTION
Read these safety instructions carefully before servicing your
engine. Most accidents are caused by failure to follow fun-
damental
rules and precautions. Know when dangerous con-
ditions exist and take the necessary precautions to protect
yourself, yourpersonnel, and your
machinery.
The following safety instructions are in compliance with the
American Boat and Yacht Council (ABYC) standards.
PREVENT ELECTRIC SHOCK
A WARNING: 00 not touch AC electrical connections
while engine is running, or when connected to shore
power. Lethal voltage is present at these connections!
• Do not operate this machinery without electrical
enclosures and covers in place.
• Shut off electrical power before accessing electrical
equipment.
• Use insulated mats whenever working on electrical
equipment.
• Make sure your clothing and skin are dry, not damp
(particularly shoes) when handling electrical equipment.
• Remove wristwatch and all jewelry when working on
electrical equipment.
• Do not connect utility shore power to vessel's AC
circuits, except through a ship-to-shore double throw
transfer switch. Damage to vessel's AC generator may
result
if this procedure is not followed.
• Electrical shock results from handling a charged
capacitor. Discharge capacitor
by shorting terminals
together with an insulated tool.
PREVENT BURNS - HOT ENGINE
A WARNING: 00 not touch hot engine parts or
exhaust system components. A running engine gets
very hot!
• Always check the engine coolant level at the coolant
recovery tank.
A WARNING: Steam can cause injury or death!
• In case of an engine overheat, allow the engine to cool
before touching the engine or checking the coolant.
PREVENT BURNS - FIRE
A WARNING: Fire can cause injury or death!
• Prevent flash fires. Do not smoke or permit flames or
sparks to occur near the fuel line, filter, fuel pump, or
other potential sources
of spilled fuel or fuel vapors. Use
a suitable container to catch all fuel when removing the
fuel line or fuel filters.
• Do not operate with a Coast GuardApproved flame
arrester removed. Backfire can cause severe injury or
death.
• Do not operate with the air cleaner/silencer removed.
Backfire can cause severe injury or death.
• Do not smoke or permit flames or sparks to occur near
the fuel system. Keep the compartment and the engine
clean and free
of debris to minimize the chance of fire.
Wipe up all spilled fuel and engine oil.
• Be aware -diesel fuel will burn.
PREVENT BURNS - EXPLOSION
A WARNING: Explosions from fuel vapors can cause
injury or death!
• Follow re-fueling safety instructions. Keep the vessel's
hatches closed when fueling. Open and ventilate cabin
after fueling. Check below for fumes/vapor before run-
ning the blower. Run the blower for four minutes before
starting your engine.
• All fuel vapors are highly explosive. Use extreme care
when handling and storing fuels. Store fuel in a well-ven-
tilated area away from spark-producing equipment and
out
of the reach of children.
• Do not fill the fuel tank(s) while the engine is running.
• Shut offthe fuel service valve at the engine when servicing
the fuel system. Take care in catching any fuel that might
spill.
DO NOT allow any smoking, open flames, or other
sources
of fire near the fuel system or engine when servic-
ing. Ensure proper ventilation exists when servicing the
fuel system.
• Do not alter or modifY the fuel system.
• Be sure all fuel supplies have a positive shutoffvalve.
• Be certain fuel line fittings are adequately tightened and
free
of leaks.
• Make sure a fire extinguisher is installed nearby and is
properly maintained. Be familiar with its proper use.
Extinguishers rated ABC by the NFPA are appropriate
for all applications encountered in this environment.
;. ;..Unlvarsal
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SAFETY INSTRUCTIONS
ACCIDENTAL STARTING
A WARNING: Accidental starting can cause injury
or death!
• Disconnect the battety cables before servicing the engine.
Remove the negative lead first and reconnect it last.
• Make certain all personnel are clear of the engine before
starting.
• Make certain all covers, guards, and hatches are
re-installed before starting the engine.
BATTERY EXPLOSION
A WARNING: Battery explosion can cause injury
or death!
• Do not smoke or allow an open flame near the battery
being serviced. Lead acid batteries emit hydrogen, a high-
ly explosive gas, which can be ignited by electrical arcing
or by lit tobacco products. Shut offall electrical
equip-
ment in the vicinity to prevent electrical arcing
during servicing.
• Never connect the negative (-) battery cable to the
positive (+) connection terminal
of the starter solenoid.
Do not test the battery condition by shorting the terminals
together. Sparks could ignite battery gases or
fuel vapors.
Ventilate any compartment containing batteries to prevent
accumulation
of explosive gases. To avoid sparks, do not
disturb the battery charger connections while the battery
is being charged.
• Avoid contacting the terminals with tools, etc., to prevent
burns or sparks that could cause
an explosion. Remove
wristwatch, rings, and any otherjewelry before handling
the
battery.
• Always turn the battery charger offbefore disconnecting
the battery connections. Remove the negative lead
first
and reconnect it last when servicing the battery.
BATTERY ACID
A WARNING: Sulfuric acid in batteries can cause
severe injury or death!
• When servicing the battery or checking the electrolyte
level, wear rubber gloves, a rubber apron, and
eye
protection. Batteries contain sulfuric acid which is
destructive. If it comes in contact with your skin, wash it
offat once with
water. Acid may splash on the skin or
into the eyes inadvertently when removing
electrolyte
caps.
ii
TOXIC EXHAUST GASES
A WARNING: Carbon monoxide (CO) isa deadly gas!
• Ensure that the exhaust system is adequate to expel gases
discharged
from the engine. Check the exhaust system
regularly
for leaks and make sure the exhaust manifold!
water-injected exhaust elbow is securely attached.
• Be sure the unit and its surroundings are well ventilated.
Run blowers when running the generator set or engine.
• Don't run the generator set or engine unless the boat is
equipped with a functioning marine carbon monoxide
detector that complies with
ABYC A-24. Consult your
boat builder or dealer for installation
of approved detectors.
• For additional information refer to ABYC T-22
(educational information on Carbon Monoxide).
A WARNING: Carbon monoxide (CO) is an invisible
odorless gas. Inhalation produces flu-like symptoms,
nausea or death!
• Do not use copper tubing in diesel exhaust systems. Diesel
fumes can rapidly destroy copper tubing in exhaust
systems. Exhaust sulfur causes rapid deterioration of
copper tubing resulting in exhaust/water leakage.
• Do not install exhaust outlet where exhaust can be drawn
through portholes, vents, or air conditioners.
If the engine
exhaust discharge outlet
is near the waterline, water could
enter the exhaust discharge outlet and close or restrict the
flow of exhaust. Avoid overloading the craft.
• Although diesel engine exhaust gases are not as toxic as
exhaust fumes from gasoline engines, carbon monoxide
gas is present in diesel exhaust fumes. Some of the
symptoms
or signs of carbon monoxide inhalation or
poisoning
are:
Dizziness Throbbing in temples
Headache Muscular twitching
Nausea
Vomiting Weakness and sleepiness Inability to think coherently
AVOID MOVING PARTS
A WARNING: Rotating parts can cause injury
or death!
• Do not service the engine while it is running. If a
situation arises in which it
is absolutely necessary to
make operating adjustments, use extreme care to avoid
touching moving parts and hot exhaust
system
components.

SAFETY INSTRUCTIONS
• Do not wear loose clothing orjewelry when servicing
equipment; tie back long hair and avoid wearing loose
jackets, shirts, sleeves, rings, necklaces or bracelets that
could
be caught in moving parts.
• Make sure all attaching hardware is properly tightened.
Keep protective shields and guards in their respective
places at
all times.
• Do not check fluid levels or the drive belt's tension while
the engine is operating.
• Stay clear of the drive shaft and the transmission coupling
when the engine is running; hair and clothing can easily
be caught in these rotating parts.
HAZARDOUS NOISE
A WARNING: High noise levels can cause hearing
loss!
• Never operate an engine without its muffler installed.
• Do not run an engine with the air intake (silencer)
removed.
• Do not run engines for long periods with their enclosures
open.
A WARNING: Do not work on machinery when you are
mentally or physically incapacitated by fatigue!
OPERATORS MANUAL
Many of the preceding safety tips and warnings are repeated
in your Operators
Manual along with other cautions and
notes to highlight critical information. Read your manual
carefully, maintain your equipment, and follow all safety pro-
cedures.
ENGINE INSTALLATIONS
Preparations to install an engine should begin with a thor-
ough examination of the American Boat and Yacht Council's
(ABYC) standards. These standards are a combination of
sources including the USCG and the NFPA.
Sections of the ABYC standards of particular interest are:
H-2 Ventilation
P-I Exhaust systems
P-4 Inboard
engines
E-9 DC Electrical systems
All installations must comply with the Federal Code of
Regulations (FCR).
ABYC, NFPA AND USCG PUBLICATIONS FOR
INSTALLING DIESEL ENGINES
Read the following ABYC, NFPA and USCG publications
for safety codes and standards. Follow their recommenda-
tions when installing your
engine.
ABYC (American Boat and Yacht Council)
Safety Standards for Small Craft
Order from:
ABYC
3069 Solomons Island Rd.
Edgewater, MD 21037
NFPA (National Fire Protection Association)
Fire Protection Standardfor Motor Craft
Order from:
NFPA
11 Tracy Drive
Avon Industrial Park
Avon, MA 02322
USCG (United States Coast Guard)
USCG 33CFR183
Order from:
U.S. Government Printing Office
Washington, D.C. 20404
4 .Univarsal
iii

INSTALLATION
When installing UNIVERSAL engines, it is important that strict attention be paid to
the following information:
CODES AND REGULATIONS
Federal regulations, ABYC guidelines and safety codes must be complied with when
installing engines and generators in a marine environment.
SIPHON-BREAK
For installations where the exhaust manifold/water-injected exhaust elbow is close to
or will be below the vessel's waterline, provisions must be made to install a siphon-
break in the raw water supply hose to the exhaust elbow. This hose must be looped a
minimum
of 20 in. (51 cm) above the vessel's waterline. Failure to use a siphon-
break when the exhaust manifoldinjection port is ator below the load waterline
will result in raw water damage to the engine and possibleflooding of the boat.
If you have any doubt about the position of the water-injected exhaust elbow relative
to the vessel's waterline under any
of the vessel's various operating conditions or
when the vessel is not underway, installa siphon-break. This precaution is necessary
to protect your engine.
NOTE: A siphon-break requires periodic inspection and cleaning to ensure proper
operation. Failure to properly maintain a siphon-break can result in catastrophic
engine damage. Consult the siphon-break manufacturer
for a proper maintenance
schedule.
EXHAUST SYSTEM
The exhaust hose must be certified for marine use. The system must be designed to
prevent water from entering the exhaust under any sea conditions and at any angle
of
the vessel's hull.
A detailed 40-page Marine Installation Manual covering gasoline and diesel,
engines and generators, is available from your UNIVERSAL dealer .
... ... Unlvarsal
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TABLE OF CONTENTS
Introduction.......................................................................................................... 2
Parts Identification............................................................................................... 3
Specifications....................................................................................................... 4
Testing for OverhauL........................................................................................... 6
Engine Troubleshooting....................................................................................... 7
Service Standards...............................................................................................
15
Engine Description............................................................................................. 18
Engine Disassembly & Reassembly................................................................... 21
Engine Service................................................................................................... 31
Engine Adjustments............................................................................................44
Exhaust Manifold Service..................................................................................48
Lubrication System Description.........................................................................49
Lubrication System Service............................................................................... 52
Cooling System Description.............................................................................. 54
Cooling System Service..................................................................................... 56
Fuel System Description.................................................................................... 58
Fuel System Disassembly & Reassembly..........................................................
63
Fuel System Service...........................................................................................64
Admiral Control
PaneL ..................................................................................... 67
Captain Control PaneL......................................................................................
68
Control Panel Troubleshooting.......................................................................... 69
Glow Plug Service............................................................................................. 71
Starter Service.................................................................................................... 72
Mando Alternator Service.................................................................................. 78
Prestolite Alternator Service.............................................................................. 88
Wiring Diagram #39144...................................................................................100
Wiring Schematic #39144................................................................................ 101
Wiring Diagram #200360 -Catalina yachts....................................................102
Wiring Schematic #200360 -Catalina yachts.................................................
103
Hurth HBW Transmissions.............................................................................. 104
Transmission Troubleshooting......................................................................... 107
Special Tools.................................................................................................... 108
Torques............................................................................................................. 110
Standard Hardware; Sealants & Lubricants..................................................... 111
Metric Conversions.......................................................................................... 112
Standard and Metric Conversion Data............................................................. 113
Index................................................................................................................. 114
1

INTRODUCTION
ENGINE OVERHAUL
This service manual contains detailed information relating
to the servicing and overhaul
of the Universal M3-20B
marine diesel engine. Information about the construction
and function
of the various systems and components can be
found in the Description sections. For the major engine
overhaul procedure, refer to the
ENGINE DISASSEMBLY &
REASSEMBLY and ENGINE SERVICE sections. Additional
service information for specific components and systems
may
be found by referring to the TABLE OF CONTENTS
and the INDEX. Refer also to your UNIVERSAL parts
Catalog.
These service procedures are intended for the guidance
of
suitably equipped and staffed marine engine service and
rebuilding facilities, and should only
be undertaken by such
facilities and their personnel.
PRODUCT SOFTWARE
Product software (tech data, parts lists, manuals, brochures
and catalogs) provided from sources other than UNIVER-
SALare not within UNIVERSAL'S CONTROL.
UNIVERSAL CANNOT BE RESPONSmLE FOR THE
CONTENT
OF SUCH SOFTWARE, MAKES NO WAR-
RANTIES OR REPRESENTATIONS WITH RESPECT
THERETO, INCLUDING ACCURACY, TIMELINESS OR
COMPLETENESS THEREOF AND WILL IN NO EVENT
BE LIABLE FORANY TYPE OF DAMAGE OR INJURY
INCURRED IN CONNECTION WITH ORARISING OUT
OF THE FURNISHING OR USE OF SUCH SOFTWARE.
UNIVERSAL customers should also keep in mind the time
span between printings
of UNIVERSAL product software
and the unavoidable existence
of earlier UNIVERSAL manu-
als. Product software provided with UNIVERSAL products,
whether from UNIVERSAL
or other suppliers, must not and
cannot
be relied upon exclusively as the definitive authority
on the respective product. It not only makes good sense but
is imperative that appropriate representatives
of UNIVER-
SAL
or the supplier in question be consulted to determine
the accuracy and currentness
of the product software being
consulted by the customer.
NOTES, CAUTIONS AND WARNINGS
As this manual takes you through the service procedures
and troubleshooting
of your marine engine, critical informa-
tion will be highlighted by NOTES, CAUTIONS, and WARN-
INGS. 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.
A WARNING: Procedures, which if not properly fol-
lowed, can result in personal injury or loss of life •
CUSTOMER IDENTIFICATION CARD
Customer Identification
UNIVERSAL OWNER
MAIN STREET
HOMETOWN, USA
Model M3-20B
Expires 9/12101
Ser. #XXXX-D608
The UNIVERSAL engine serial number is an alphanumeric
number that can assist in determining the date
of manufac-
ture of your UNIVERSAL engine. The manufacturer's date
code is placed at the end
of the engine serial number and
consists
of a character followed by three numbers. The
character indicates the decade (D=1990s, E=20oos), the first
number represents the year in the decade, and the second
and third numbers represent the month
of manufacture.
ORDERING PARTS/SERIAL NUMBER LOCATION
Whenever replacement parts are needed, always provide
the engine model number and engine serial number as they
appear on the silver and black identification nameplate
located on the side
of the engine's exhaust manifold. The
engine serial number can also
be found stamped into the
engine block on the left side
of the engine below the cylin-
der head cover. You must provide us with this information
so we may properly identify your engine. In addition,
include a complete part description and part number for
each part needed (see the separately furnished Parts List).
Also insist upon UNIVERSAL packaged parts because will
fit or generic parts are frequently not made to the same
specifications as original equipment.
~
NOTE: Component locations in this manual are referenced
from thefront
of the engine which is the pulley/drive belt
end.
Left and right sides are determined as follows: imag-
ine straddling the engine, facing in the same direction as
thefront
of the engine: the left side is at your left, the right
side is
at your right. The cylinder number sequence starts
with the No. I cylinder located
at thefront of the engine.
• • Unlvanal
MARINE POWER
2

OIL
FILTER
PARTS IDENTIFICATION
MODEL M3-20B
STARTER
SOLENOID
FUEL LIFT
PUMP
3
ALTERNATOR
;;:yr~~I--- COOLANT PUMP
SHEAVE

ENGINE
Engine Type
Horsepower
Cylinders
Aspiration
Bore & Stroke
Combustion Chamber
Displacement
Compression Ratio
Firing Order
Crankshaft Direction of Rotation
Maximum Torque
Dry Weight, with Transmission
Dimensions
Maximum Angle of Installation
Maximum Angle of Rotation
Engine Speed
Engine Timing
Engine Stop
LUBRICATION SYSTEM
Type of System
Oil Grade
Oil Filter
Lubricant Capacity
Operating Oil Pressure (Engine Hot)
FUEL SYSTEM
Type of System
Fuel
Fuel
Injection Pump
Fuel Injectors
Governor
Fuel Lift Pump
Fuel Filter
Fuel Supply & Return Piping
Typical Fuel Consumption
@3000 rpm
Air Intake Silencer
Air Flow @ 3600 rpm
(Engine Combustion)
SPECIFICATIONS
UNIVERSAL MODEL M3-20B
Diesel, four-cycle, fresh water cooled, vertical, in-line overhead valve mechanism
20@3600 rpm
3
Naturally aspirated
2.64 x 2.68 in. (67 x 68 mm)
Spherical type; three vortex combustion system
43.8 cu. in. (0.7177 liters)
23:1
1- 2- 3
Counterclockwise as viewed from flywheel end
33 ft-Ibs (4.6 kg-m) @ 2500 rpm
241 Ibs (110 kg)
Length: 26.4 in. (670.6 mm) Width: 18.8 in. (477.5 mm) Height: 20.1 in. (510.6 mm)
Not to exceed 14° (24 rad.)
Not to exceed 25° (44 rad.)
Idle speed: 1,000 - 1,200 rpm. Cruise Speed: 2,500 - 3,000 rpm. Maximum Speed: 3,500 - 3,600 rpm.
18° (0.314 rad.) before lD.C.
Manual
Forced lubrication by gear pump
API Specification CF or CG-4, SAE 30, 10W-30, 15W-40
Full-flow, spin-on filter element
4.0 qts (3.8 liters)
40-60 psi (2.8 - 4.2 kg/cm2) (276-414 kPa)
Open flow, self priming
No.2 Diesel Oil, cetane rating of 45 or higher
Bosch in-line plunger type
Bosch throttle type
Centrifugal ball mechanical type
12 volt 5 ft. lift capacity, solid state
Full flow, spin-on element
1/8 in. I.D. (3.18 mm) minimum; 3/8 in. I.D. (9.52 mm) maximum
0.75 gaL/hr. (2.83 liters/hr.)
Cleanable, replaceable filter element
45.8 cubic feeVminute (1.3 cubic meters/minute)
...... Unlvarsal
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(continued)

SPECIFICATIONS
UNIVERSAL MODEL M3-20B
COOLING SYSTEM
Type of System
Fresh water cooled block, thermostatically controlled with raw water heat exchanger and
centrifugal fresh water pump
Operating Temperature 170° - 190° F (77° - 88°C)
Coolant Pump
Centrifugal type, metal impeller, belt-driven
Coolant Capacity 3.75 quarts (3.50 liters)
Raw Water Pump
Positive displacement, neoprene impeller, gear driven
Raw Water Flow @ 3000 rpm
before discharge into exhaust elbow
7.0 gal/min. (26.5 liters/min.)
ELECTRICAL SYSTEM
Starting Battery
12 volt DC, negative ground
Battery Capacity 400 - 600 cold cranking amps (CCA)
Alternator/Regulator
Mando, 51 amp, 12 volt, belt-driven, with internal regulator
Starter Motor
12 volt, reduction gear, actuated shift, with solenoid
Starting Aid
12 volt sheathed type glow plugs
TRANSMISSION
Model
HURTH HBW-50-2R
Type of Transmission
Case-hardened helical gears, with a servo-operated multiple disc clutch
Gear Ratio Forward (Std) 2.05:1
Propeller Shaft Rotation
Right hand - standard transmission
Lubrication Fluid
ATF type A, Dextron II or Dextron III
Transmission Sump Capacity
0.37 qt. (0.35 liter)
5

TESTING FOR OVERHAUL
HOW TO DETERMINE WHEN
TO OVERHAUL THE ENGINE
Cause 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,
in the case ofdiesel engines, is not necessarily due to trouble
with the engine itself, but is sometimes caused by injector
nozzle wear or injection pump
wear. It is most reasonable to
judge by a decrease in compression pressure. The decrease in
compression pressure is caused by many factors. It is, there-
fore, necessary to determine a cause or causes on the basis of
data 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 pis-
ton rings, the following symptoms will occur:
• Low engine power output
• Increased fuel consumption
• Increased oil consumption
• Hard engine starting
• Noisy engine operation
These symptoms often appear
together. Increased fuel con-
sumption and hard engine starting can also result from exces-
sive fuel injection, improper injection timing, and wear of
the
injection pump and nozzles. They are also caused by defec-
tive electrical components such
as the battery, alternator,
starter
and glow plugs. Therefore it is desirable to judge the
optimum engine overhaul time by the lowered compression
pressure caused
by worn cylinders and piston rings plus
increased oil consumption. In diesel engines, satisfactory
combustion
is obtained only under sufficient compression
pressure.
If an engine lacks compression pressure, incomplete
combustion offuel will take place even ifother parts of
the
engine are operating properly. To determine the period of
engine overhaul, it
is important to measure the engine com-
pression pressure regularly. At the same time, the engine
speed at which the measurement ofcompression pressure
is
made should be checked because the compression pressure
varies with engine
rpm. The engine rpm can be measured at
the front end of the crankshaft.
6
Measuring Compression Pressure
To check the compression pressure, see ENGINE COMPRES-
SION TESTunder ENGINEADJUSTMENTS.
NOTE: Do notguess the conditions of othercylindersfrom a
result
of testing one cylinder. Be sure to measure the com-
pression pressure
for each cylinder. Look for cylinders with
dramatically (at least 20%) lower compression than the aver-
age
of the other cylinders. If the weak cylinder isflanked by
healthy cylinders, the problem is either valve-
or head-gasket
related.
Very low compression in an adjacent cylinder indi-
cates gasketfailure. Abnormally high readings on all cylin-
ders indicate heavy carbon accumulations, a condition that
might be accompanied
by high pressures and noise.
NOTE: In case of severe vibrations and detonation noise,
have the injectors overhauled
by an authorizedfuel injection
service center. Poorfuel quality, contaminants,
and loss of
positivefuel pressure to the injection pump will result in
injectorfaults.
OVERHAUL CONDITIONS
Compression pressure tends to increase a little in a new
engine until the piston rings and valve seats have been bro-
ken
in. Thereafter, it decreases gradually with the progressive
wear ofthese parts.
When
the decrease ofcompression pressure reaches its limit
(see SERVICE STANDARDS), the engine must
be over-
hauled. The engine also requires an overhaul when oil con-
sumption
is high, when blowby is evident, and when
compression values are at a minimum or below.
NOTE: Referto the SERVICESTANDARDS chart during an
engine overhaul. It gives the measurements and values for
the repair or replacement of the engine components.
NOTE: The ENGINE TROUBLESHOOTING section may be
helpful in determining the
need for an engine overhaul.

ENGINE TROUBLESHOOTING
The following troubleshooting table describes certain problems
relating
to engine service, the probable causes ofthese prob-
lems, and the recommendations to overcome these problems.
NOTE: The engine:V electrical system is protected by a 20
ampere manual reset circuit breaker located on a bracket.
The preheat solenoid is mounted on the same bracket.
PROBLEM
HARD STARTING
PROBABLE CAUSE
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 FUEL INJECTION SYSTEM
1. No fuel at injectors.
a. No fuel in fuel tank and/or fuel shutoff.
b. Fuel filter or fuel line clogged.
c. Injection pump faulty.
d. Loose injection line retaining nut.
2. Fuel injectors faulty; inadequate spray.
3. Low injection pressure.
4. Injection timing incorrect.
5. Poor quality fuel.
6. Water and/or air in fuel system.
MAIN ENGINE TROUBLES
1. Low compression.
a. Leaking compression from fuel injector gasket.
b. I ncorrect valve clearance.
c. Inadequate contact of valve seat.
d. Valve stem seized.
e. Weak or broken valve spring.
f. Bent push rod.
g. Compression leaks through cylinder head gasket.
h. Cracked or worn piston.
i. Piston ring seized.
j. Worn piston ring or cylinder liner.
It Cracked or distorted cylinder head.
I. Fuel camshaft worn.
2. Carbon accumulation in combustion chamber.
+ ,;"UnlvQI'sal
7
VERIFICATION/REMEDY
1. Replace engine oil with less viscous oil.
2. Recharge battery.
3. Replace battery.
4. Clean terminals and tighten cables.
5. Repair or replace starter.
1. Check a. through e.
a. Fill fuel tank. Open shutoff and bleed system.
b. Replace filter and bleed. Clean fuel line.
c. Inspect pump. Repair or replace pump as
needed.
d. Tighten nut.
2. Remove and test nozzles. Repair nozzles as
needed.
3. Adjust injection pressure.
4. Check and adjust timing.
5. Drain and replace with proper fuel.
6. Remove water and/or bleed air from fuel system.
Check fuel system for leaks and fuel tank for
water contamination.
1. Check a. through k.
a. Tighten fuel injector or replace gasket.
b. Adjust valve clearance.
c. Lap valve.
d. Replace valve and valve guide.
e. Replace valve spring.
f. Replace push rod.
g. Replace gasket.
h. Replace piston.
i. Replace piston and piston ring.
j. Replace piston ring or cylinder liner.
It Replace cylinder head.
I. Replace fuel camshaft.
2. Clean.
(continued)

ENGINE TROUBLESHOOTING
PROBLEM
PROBABLE CAUSE
VERIFICATION/REMEOY
ENGINE IDLING
1. Idle speed too low. 1. Adjust idle stop as needed.
TOO LOW
2. Fuel filter clogged. 2. Replace filter and bleed fuel system.
3. Incorrect injection pump timing.
3. Check timing and adjust as needed.
4. High pressure injection line leaking.
4. Slacken attaching nut and retighten.
5. Fuel injector leaking at sealing gasket in head. 5. Retighten injector and/or replace sealing washer.
6. Injection nozzle not operating properly.
6. Check nozzle and adjust as needed.
7. Engine air intake obstructed. 7. Check air intake silencer and air flow into
engine compartment.
ROUGH IDLING
MALFUNCTION OF ENGINE-RELATED COMPONENTS
1. Improper valve clearance.
1. Adjust clearance.
2. Poor valve to valve seat contact.
2. Repair or replace valve.
3. Failure of cylinder head gasket.
3. Replace gasket.
4. Governor malfunctioning.
4. Repair governor.
FUEL INJECTION SYSTEM PROBLEM
1. Faulty idling speed.
1. Adjust idling speed.
2. Faulty injection timing.
2. Adjust injection timing.
3. Clogged fuel line or fuel filter.
3. Clean fuel line or replace fuel filter.
4. Leak in fuel line or fuel filter.
4. Repair fuel line or replace fuel filter.
5. Air in injector, fuel line, injection pump, fuel filter
or fuel filter/water separator.
5. Bleed air.
6. Seized or leaky delivery valve.
6. Clean or replace delivery valve.
7. Faulty injection starting pressure.
7. Adjust starting pressure.
8. Injection nozzle malfunction.
8. Clean or replace injection nozzle.
9. Feed pump malfunction.
9. Clean or replace feed pump.
10. Injection pump malfunction.
10. Take to a fuel injection pump service facility,
or replace the pump.
ENGINE SLOWS 1. Fuel lift pump failure.
1. Check fuel lift pump operation.
AND STOPS
2. Switches and/or wiring loose or disconnected.
2. Inspect wiring for short circuits and loose
connections. Inspect switches for proper
operation.
3. Fuel starvation.
3. Check fuel supply, fuel valves, fuel lift pump.
4. 20 amp circuit breaker tripping.
4. Check for high DC amperage draw during
operation. Ensure breaker is not overly sensi-
tive to heat which would cause tripping.
5. Exhaust system is restricted.
5. Check for blockage, collapsed hose, carbon
buildup at exhaust elbow.
6. Water in fuel.
6. Pump water from fuel tank(s); change filters
and bleed fuel system.
(continued)
8

ENGINE TROUBLESHOOTING
PROBLEM
PROBABLE CAUSE VERIFICATION/REMEOY
LOW OUTPUT
LOW COMPRESSION See Low Compression under 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. Bleed and check for source.
2. Clogged filter. 2. Clean or replace filter element.
3. Contaminated or inferior fuel. 3. Purge fuel system and replace with quality
fuel.
4. Contaminated fuel tank. 4. Clean fuel tank.
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.
4. Add engine oil.
OTHER
1. Insufficient intake air. 1. Increase engine compartment air supply.
KNOCKING
ENGINE KNOCKS WITHOUT MUCH SMOKE
1. Main engine troubles.
1. Check a. and b.
a. Overheated cylinder.
a. See ENGINE OVERHEATS/SHUTS
DOWN; LOW OUTPUT.
b. Carbon deposits in cylinder.
b. Clean.
2. Injection timing too early.
2. Correct the timing.
3. Injection pressure too high.
3. Correct the pressure.
4. Improper fuel.
4. Replace with proper fuel.
KNOCKING WITH DARK SMOKE
1. Poor compression.
1. See Low Compression under HARD
STARTING.
2. Injection pump malfunctioning.
2. AdjusVRepair.
3. Nozzle malfunctioning.
3. Check a. through d.
a. Poor spray.
a. Clean or replace nozzle.
b. Chattering.
b. Repair or replace nozzle.
c. After-injection drip.
c. Repair or replace nozzle.
d. Nozzle needle valve seized.
d. Replace needle valve.
ABNORMAL SOUND
CRANKSHAFT AND MAIN BEARING
OR NOISE
1. Badly worn main bearing. 1. Replace bearing and grind crankshaft.
2. Badly worn crankshaft. 2. Grind crankshaft.
3. Melted bearing. 3. Replace bearing and check lubrication system.
4. Excessive crankshaft end play. 4. Repair or replace crankshaft.
(continued)
9

PROBLEM
ABNORMAL SOUND
OR NOISE (Cont'd)
ROUGH OPERATION
(HUNTING)
ENGINE TROUBLESHOOTING
PROBABLE CAUSE
CONNECTING ROD AND CONNECTING ROD BEARING
1. Worn connecting rod big end bearing.
2. Worn crankpin.
3. Bent connecting rod.
4. Excessive connecting rod bearing oil clearance.
5. Connecting rod bearing seized or heat-damaged.
PISTON, PISTON PIN, PISTON RING, CYLINDER LINER
1. Worn cylinder liner.
2. Worn piston or piston pin.
3. Piston seized.
4. Piston seized and ring worn or damaged.
VALVES OR TIMING-RELATED PARTS
1. Worn camshaft.
2. Excessive valve clearance.
3. Worn timing gear.
4. Broken valve spring.
5. Excessive clearance between rocker arm and
bushing.
6. Excessive clearance between idler gear bushing and
spindle.
FUEL SYSTEM
1. Poor quality and/or incorrect fuel.
2. Incorrect injection timing. Timing too advanced.
3. Fuel injector stuck open.
OTHER
1. Coolant pump bearing worn or seized.
2. Improper drive-belt tension.
3. Malfunction of alternator bearing.
4. Exhaust gas leakage.
INJECTION PUMP
1. Uneven injection.
2. Inadequate injection nozzle spray.
GOVERNING SYSTEM
1. Governor lever malfunctioning.
2. Fatigued governor spring.
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10
VERIFICATION/REMEOY
1. Replace bearing.
2. Grind crankshaft.
3. Correct bend or replace.
4. Repair or replace bearing.
5. Replace bearing.
1. Repair or replace liner.
2. Replace piston.
3. Replace piston and rebore cylinder.
4. Replace piston and rings.
1. Replace camshaft.
2. Adjust valve clearance.
3. Replace timing gear.
4. Replace valve spring.
5. Replace bushing.
6. Replace bushing.
1. Use No.2 diesel fuel.
2. Check and correct injection timing.
3. Locate and remove faulty injector. Rebuild or
replace.
1. See Coolant Pump under COOLING SYSTEM.
2. Adjust.
3. See Alternator Troubleshooting under
DC ELECTRICAL SYSTEM.
4. Repair.
1. Adjust injection or replace parts.
2. Replace injection nozzle.
1. Check governor shaft and adjust.
2. Replace spring.
(continued)

ENGINE TROUBLESHOOTING
PROBLEM
PROBABLE CAUSE
VERIFICATION/REMEDY
SMOKY EXHAUST
WHITISH OR PURPLISH
1. Engine is running cold. 1. Warm-up engine.
2. Excessive engine oil. 2. Correct oil level.
3. Excessive rise of oil into combustion chamber. 3. Check 3. through f.
3. Poor piston contact. 3. Check.
b. Piston ring or liner worn or seized. b. Clean or replace.
c. Excessive piston-to-cylinder clearance. c. Correct or replace.
d. Worn valve stem and valve guide. d. Replace valve stem and guide.
e.
Low engine oil viscosity. e. Replace engine oil.
f.
Excessive oil pressure. f. I nspect the lubrication system. See
LUBRICATION SYSTEM.
4. Injection timing is too late. 4. Adjust timing.
5. Insufficient compression. 5. See Low Compression under HARD STARTING.
BLUE
1. Incorrect grade of engine oil.
1. Use the correct grade of oil; see Oil Grade
under SPECIFICATIONS.
2. Crankcase is overfilled with engine oil (oil is blow- 2. Decrease oil level.
ing out through the exhaust).
BLACKISH OR DARK GRAYISH
1. Poor compression. 1. See Low Compression under HARD STARTING.
2. Improper valve clearance. 2. Adjust valve clearance.
3. Improper injection timing.
3. Adjust injection timing.
4. Improper fuel. 4. Replace with proper fuel.
5. High back-pressure in exhaust. 5. Check for restrictions in exhaust system.
6. Insufficient intake air. 6. Increase engine compartment air supply.
7. Overload. 7. Reduce load.
BLACK, LARGE AMOUNT
1. Clogged fuel filter.
1. Replace fuel filter and bleed system.
2. Restricted air intake.
2. Remove air obstruction.
3. Engine overloaded.
3. Check engine propeller size and engine
performance no-load through fully loaded.
4. Injection timing.
4. Check the injection pump timing and adjust as
needed.
5. Fuel injectors not operating properly.
5. Check nozzle spray pressure setting.
6. Improper grade of fuel. 6. Use specified grade of fuel.
EXCESSIVE
EXHAUST SMOKE
1. Faulty injection timing. 1. Adjust timing.
2. Water in injection pump, fuel filter or fuel filter/water
2. Drain fuel system.
separator.
3. Faulty injection starting pressure. 3. Adjust starting pressure.
4. Injection pump malfunctioning. 4. Replace injection pump.
(continued)
11

PROBLEM
INTERMITTENT
EXHAUST SOUND
EXCESSIVE FUEL
CONSUMPTION
EXCESSIVE OIL
CONSUMPTION
ENGINE TROUBLESHOOTING
PROBABLE CAUSE
1. Fuel filter clogged.
2. Fuel line sucks air.
3. Water mixed in fuel.
ENGINE PROBLEMS
1. Noisy knocking.
2. Smoky exhaust.
3. Moving parts nearly seized or excessively worn.
4. Poor compression.
5. Improper valve timing.
6. Improper valve clearance.
INSUFFICIENT INTAKE AIR
1. Air intake obstructed.
FUEL INJECTION PROBLEMS
1. Injection timing incorrect.
2. Faulty injection starting pressure.
3. Seized nozzle.
4. Worn nozzle.
5. Nozzle leaking.
6. Injector not operating properly.
7. Clogged fuel filter.
8. High idling speed.
FUEL PROBLEMS
1. Improper fuel.
2. Fuel leaks.
ENGINE OVERLOADED
1. Propeller size.
OIL LEAKAGE
1. Defective oil seals.
2. Broken gear case gasket.
3. Loose gear case attaching bolts.
4. Loose drain plug.
5. Loose oil line connector.
6. Broken rocker cover gasket.
7. Loose rocker cover attaching bolts.
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12
VERIFICATION/REMEDY
1. Clean or replace filter.
2. Retighten fuel line joints or replace fuel line.
3. Replace fuel.
1. See KNOCKING.
2. See SMOKY EXHAUST.
3. Repair or replace.
4. See Low Compression under HARD STARTING.
5. Adjust timing.
6. Adjust clearance.
1. Remove obstruction.
1. Adjust timing.
2. Adjust starting pressure.
3. Replace nozzle.
4. Replace nozzle.
5. Tighten nozzle or replace sealing gasket.
6. Adjust nozzle spray pressure.
7. Replace filter.
8. Adjust idling speed.
1. Replace with proper fuel.
2. Find fuel leaks.
1. Check propeller size and engine performance
at rated rpm.
1. Replace oil seals.
2. Replace gasket.
3. Retighten bolts.
4. Retighten plug.
5. Retighten oil line connections.
6. Replace gasket.
7. Retighten attaching bolts.
(continued)

PROBLEM
EXCESSIVE OIL
CONSUMPTION
(cont'd)
LOW OIL PRESSURE
HIGH OIL PRESSURE
FUEL MIXED INTO
LUBE OIL
COOLANT MIXED INTO
LUBE OIL
ENGINE OVERHEATS!
SHUTS DOWN
ENGINE TROUBLESHOOTING
PROBABLE CAUSE
OIL LEVEl RISING
1. Incorrectly positioned piston ring gaps.
2. Displaced or twisted connecting rod.
3. Worn piston ring, or piston ring groove.
4. Oil ring worn or stuck.
5. Worn piston or cylinder liner.
6. Worn crankshaft bearing and crankpin bearing.
OIL LEVEL FALLING
1. Defective stem seal.
2. Worn valve and valve guide.
1. Worn main or connecting rod bearings.
2. Relief valve malfunction.
3. Diesel fuel is diluting the oil.
4. Oil strainer clogged.
5. Excessive oil clearance of crankshaft bearing.
6. Excessive oil clearance of crankpin bearing.
7. Excessive oil clearance of rocker arm bearing.
8. Oil passage clogged.
9. Improper grade of oil.
10. Oil filter cartridge clogged.
11. Oil pump defective.
1. Relief valve defective.
2. Improper grade of oil.
1. Injection pump plunger worn.
2. Deficient nozzle injection.
3. Injection pump malfunction.
1. Defective cylinder head gasket.
2. Defective cylinder head or cylinder block.
1. V-belt slackening or slippery with oil.
2. Low oil level or poor oil quality.
3. Knocking.
4. Moving parts seized or damaged.
5. Lack of coolant.
6. Raw water not Circulating.
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13
VERIFICATION/REMEDY
1. Correct ring gap positions.
2. Replace connecting rod.
3. Replace ring or piston.
4. Replace oil ring.
5. Repair or replace.
6. Replace.
1. Replace stem seal.
2. Replace valve and valve guide.
1. Replace bearings.
2. Overhaul oil pump.
3. Injection pump repair.
4. Clean oil strainer.
5. Replace crankshaft bearing.
6. Replace crankpin bearing.
7. Replace rocker arm bearing.
8. Clean oil passage.
9. Replace with specified grade of oil.
10. Replace.
11. Repair or replace.
1. Overhaul oil pump.
2. Replace with specified grade of oil.
1. Replace pump element or injection pump.
2. Repair or replace nozzle.
3. Replace injection pump.
1. Replace cylinder head gasket.
2. Replace cylinder head or cylinder block.
1. Adjust, replace or clean belt.
2. Add or change oil.
3. See KNOCKING.
4. Replace.
5. Add coolant.
6. Check a. and b.
a. Raw water pump failure. Check impeller;
replace if necessary.
b. Obstruction at raw water intake or raw water
filter.
(continued)

PROBLEM
ENGINE OVERHEATS!
SHUTS DOWN
(cont'd)
ENGINE TROUBLESHOOTING
PROBABLE CAUSE
7. Coolant not circulating.
• • Unlvarsal
14
VERIFICATION/REMEDY
7. Check a. through d.
a. Thermostat - remove and test in hot water.
Replace thermostat.
b. Loss of cpolant - check hoses, hose clamps,
drain plug, etc. for leaks.
c. Broken or loose belt - tighten/replace.
d. Air leak in system; run engine and open the
pressure cap to bleed air. Add coolant as
needed .