Onan L Series User manual

Service
Manual
L series
DieselEngine
934-0750
6-86
Printed in USA.

Important Safety Precautions
Read andobservethese safety precautionswhen using
or working on electric generators, engines and related
equipment. Also read and follow the literatureprovided
withthe equipment.
Proper operationand maintenanceare criticalto perfor-
manceand safety. Electricity, fuel, exhaust, moving parts
and batteries present hazards that can cause severe
personalinjuryor death.
FUEL, ENGINEOIL, AND FUMES ARE
FLAMMABLEAND TOXIC
Fire, explosion, and personal injury can resultfrom im-
properpractices.
Used engine oil, and benzene and lead, found in
some gasoline, havebeen identifiedby government
agencies as causing cancer or reproductivetoxicity.
When checking, drainingor adding fuel or oil, do not
ingest, breathe the fumes, or contact gasoline or
usedoil.
Do notfilltanks with engine running. Do not smoke
around the area. Wipe up oil or fuel spills. Do not
leave ragsinenginecompartment or on equipment.
Keepthisand surroundingarea clean.
Inspectfuel systembeforeeach operation and peri-
odically while running.
Equipfuel supply with a positivefuel shutoff.
Do not store or transport equipmentwith fuel intank.
Keepan ABGrated fire extinguisheravailable near
equipmentand adjacent areas for use on alltypes of
fires except alcohol.
Unlessprovidedwith equipment or notedotherwise
in installationmanual, fuel lines must becopper or
steel, secured, free of leaks and separated or
shieldedfrom electricalwiring.
Useapproved, nonconductiveflexible fuel hosefor
fuel connections. Do not usecopper tubing as aflex-
ible connection. Itwill work-harden and break.
EXHAUST GAS ISDEADLY
Engine exhaust contains carbon monoxide (CO),
an odorless, invisible, poisonous gas. Learn the
symptomsof CO poisoning.
Neversleepinavessel, vehicle, or roomwith agen-
set or engine runningunlessthe area is equipped
with an operating CO detector with an audible
alarm.
Eachtime the engine or gensetisstarted, or at least
every day, thoroughly inspectthe exhaust system.
Shutdownthe unit andrepair leaksimmediately.
Warning: Engineexhaust is known to the State of
Californiato cause cancer, birthdefects and other
reproductiveharm.
Make sure exhaust is properly ventilated.
Vessel bilge must have an operating power
exhaust.
Vehicle exhaust system must extend beyond ve-
hicle perimeter and not near windows, doors or
vents.
Do not use engineor genset coolingair to heat an
area.
Do not operate enginelgenset in enclosed area
without amplefresh air ventilation.
Expel exhaust away from enclosed, sheltered, or
occupiedareas.
Make sure exhaust system components are se-
curelyfastenedand notwarped.
MOVING PARTS CAN CAUSESEVERE
PERSONAL INJURY OR DEATH
Do not remove any guardsor coverswith the equip-
ment running.
Keephands, clothing, hair, andjewelry away from
movingparts.
Before performing any maintenance, disconnect
battery (negative
[-I cablefirst) to preventacciden-
tal starting.
Makesure fasteners andjoints are secure. Tighten
supports and clamps, keepguards in positionover
fans, drive belts, etc.
If adjustments must be made while equipment is
running, useextreme caution around hot manifolds
and moving parts, etc. Wear safety glasses and pro-
tectiveclothing.
BATTERYGAS IS EXPLOSIVE
Wear safety glassesand do not smokewhileservic-
ingbatteries.
Always disconnect battery negative
(-) lead first
andreconnect itlast. Makesure you connect battery
correctly. Adirect short across batteryterminalscan
causean explosion. Do not smokewhile servicing
batteries. Hydrogengas given off duringcharging is
explosive.
Do notdisconnect or connect battery cables
if fuel
vaporsare present. Ventilate the areathoroughly.

DO NOT OPERATE IN FLAMMABLEAND
EXPLOSIVE ENVIRONMENTS
Flammablevapor can be ignitedby equipmentoperation
or cause a diesel engineto overspeed and become diff
i-
cultto stop, resulting in possible fire, explosion, severe
personal injuryand death. Do not operatediesel equip-
mentwhere a flammable vapor environment can be
createdbyfuel spill, leak, etc., unlessequipped with
anautomatic safety device toblocktheair intakeand
stoptheengine.
HOT COOLANT CAN CAUSE SEVERE
PERSONAL INJURY
Hot coolant is under pressure. Do not loosen the
coolant pressurecapwhile the engine is hot. Let the
enginecool before openingthe pressurecap.
ELECTRICALSHOCK CAN CAUSE SEVERE
PERSONAL INJURY OR DEATH
Do not service control panelor enginewith unit run-
ning. Highvoltages are present. Work that must be
done while unit is runningshould be done only by
qualifiedservice personnel.
Do not connect thegenerator set to the publicutility
or to any other electricalpower system. Electrocu-
tioncan occur at a remotesite where line or equip-
ment repairsare beingmade. An approvedtransfer
switch must be used if morethan one powersource
isconnected.
Disconnectstarting battery (negative
[-I cablefirst)
before removingprotectiveshields or touching elec-
tricalequipment. Use insulativemats placedon dry
wood platforms. Do notwear jewelry, dampclothing
or allow skin surface to be damp when handling
electricalequipment.
Use insulatedtools. Do not tamper with interlocks.
Follow all applicable state and local electrical
codes. Haveall electricalinstallationsperformedby
a qualifiedlicensedelectrician. Tag open switches
to avoidaccidentalclosure.
With transfer switches, keep cabinet closed and
locked. Only authorized personnel should have
cabinet or operationalkeys. Due to serious shock
hazardfrom highvoltageswithincabinet, all service
andadjustmentsmust be performedby an electri-
cianor authorizedservice representative.
Ifthe cabinet must be opened for any reason:
1. Move genset operation switch or StopIAutol
Handcrankswitch (whicheverapplies) to Stop.
2. Disconnectgenset batteries(negative [-I lead
first).
3. Remove AC power to automatic transfer
switch. If instructions require otherwise, use
extremecautiondue to shock hazard.
MEDIUMVOLTAGE GENERATOR SETS
(601 V TO 15kV)
Medium voltage acts differently than low voltage.
Specialequipmentandtrainingare requiredto work
on or aroundmedium voltage equipment. Operation
and maintenance must be done only by persons
trained and qualified to work on such devices. Im-
proper use or procedureswill result in severe per-
sonal injury or death.
Donot work on energizedequipment. Unauthorized
personnel must not be permitted near energized
equipment. Induced voltage remains even after
equipment isdisconnected from the power source.
Plan maintenance with authorized personnel so
equipment can be de-energized and safely
grounded.
GENERALSAFETY PRECAUTIONS
Do not work on equipmentwhen mentallyor physi-
cally fatigued or after consumingalcohol or drugs.
Carefullyfollow allapplicablelocal, state andfeder-
al codes.
Neverstep on equipment(as when enteringor leav-
ing the engine compartment). It can stress and
break unit components, possibly resulting in dan-
gerous operating conditionsfrom leakingfuel, leak-
ing exhaustfumes, etc.
Keepequipmentandareaclean. Oil, grease, dirt, or
stowed gear can cause fire or damage equipment
byrestrictingairflow.
Equipment owners and operators are solely re-
sponsible for operating equipment safely. Contact
your authorizedOnanICumminsdealer or distribu-
tor for moreinformation.
KEEP THIS DOCUMENT NEAR EQUIPMENT FOR
EASY REFERENCE.

Safety Precautions
It is recommended that you read your engine manual and
become thoroughly acquainted with your equipment before
you
start the engine.
This symbd mlbn to a hazard or
/I ~nS8kpractice which can result in
severe personal iniury or
death.
Thk symbol refers to a hazard or
unsafe practice which can result in
personal injury or product or pmW
damage.
Fuels, electrical equipment, batteries. exhaust gases and
moving parts present potential hazards that can result in
serious, personalinjury.Take careinfollowingtheserecom-
mendedprocedures.All local,stateandfederalcodesshould
beconsultedandcompliedwith.
Thh engine is not designed or in-
I to/ ,or usein any type of airera&
Useof thisengineinaircraftcanmsullinenginefailurn
and causer sodous personal injury or Wth.
Gonemi
Provideappropriatefireextinguishersandinstallthem in
convenientlocations.
Use an extinguisherratedABC by
NFPA.
Makesurethatallfastenerson
the enginearesecureand
accurately torqued. Keep guards in positionover fans
driving
belts, etc.
Ifitisnecessarytomakeadjustmentswhiletheengineis
running,useextremecautionwhenclose
to hotexhausts.
moving
parts, etc.
Prote~tA~MovingP~
Do notwear loose clothinginthevicinityof moving parts,
such as PTO shafts, flywheels, blowers, couplings,fans,
Wts. etc.
Keep your handsaway from moving parts.
Battah
Beforestartingwork on theengine, disconnect batteries
to preventinadvertentstartingof the engine.
DO NOT SMOKE while servicing
batteria Lead acid
batteries giveoff a highlyexplosivehydrogengas which
can
be ignitedbyflame. dectricalarcingor by smoking.
Verify barn polarity before connm battery cables
Connectnegativecabiotast
Fud Systm
DO NOTfillfueltanks whileengine isrunning.
DO NOTsmokeor useanopenflameinthevicinityof the
engineorfueltank Internalcombustionenginefuelsant
highlyflamfnabl8.
Fuellines must
be of steel piping, adequately secured, ..
and free from leaks. Piping at the engine should be
approved flexible line. Do not use copper piping for
flexible lines as copper will work harden and become
brittleenough to break.
Be sureallfuel supplies have a positiveshutoff valve.
Exhaust System
Exhaust productsof any internalcombustionengineare
toxicandcan causeinjury,ordeath ifinhaled.All engine
applications. especially those within a confined area,
should
be equippedwithanexhaustsystemtodischarge
gasesto the outsideatmosphere.
Do notuseexhaustgasesto heat a compartment.
Make sure that your exhaust system is free
of leaks.
Ensure that exhaust manifolds are secure and are not
warped by
bolts unevenlytorqued.
Exhaust Gas h Dudlyl
Exhaust gases contain carbon monoxide, a poisonous gas
that can cause unconsciousnessanddeath. Itisan odorless
andcolorlessgas formedduringcombustionof hydrocarbon
fuels. Symptomsof carbonmonoxidepoisoningare:
Dizziness Vomiting
Headache MuscularTwitching
W- aMSleepiness ThrobbinginTemples
Ifyouexperienceany ofthesesymptoms.getoutintofreshair
immediately, shut down the unitand do not use until
it has
been inspected.
The best protectionagainst carbon monoxide inhalation is
proper installation and regular, frequent inspections of the
completeexhaustsystem. If you noticeachangeinthesound
or appearance of exhaust system. shut the unit down
immediatelyandhave it inspectedand repairedatonceby a
competent mechanic.
codkr0a-n
Coolantsunderpressurehaveahigherboilingpointthan
watetr. 00 NOT open a radiator pressure cap when
coolant temperature is above 212OF
(lOO°C) or while
engineisrunning
Keoptheltnitmd~AnrCkan
Makesurethatoilyragsarenotleftonor neartheengine.
Remove all unnecessary grease and oil from the untt
Accumulatedgre8seand
oil cancause overheating and
subsequentengine
damage and presenta potential fire
haz8a

Foreword
Thismanual is designed toassistall servicepersonnel withthemaintenance and overhaul of Onan L series
dieselengines. Itpresentsadescription ofeachsystemsfunctiontogether withinstructions onservicing and
overhaul procedures. A
DIMENSIONS AND CLEARANCES SECTION is provided and must be closely
followed whenoverhauling or servicing any part of engine.
Unless otherwise specified the information applies to all
L diesel engines. Whereinformation applies to a
specific engine it is so noted.
These engines have a counterclockwise rotation when viewed from the rear, flywheel end of engine.
Throughoutthismanual, "right-handMand"left-handMsidesaredetermined by facing thedriveend (flywheel)
of engine.
The manner in which the engine is operated and the maintenance performed on it will determine its
performance, safety, and durability. Equally important is the use of proper procedures during engine over-
haul. Beforeoperating,servicing, or beginningan overhaul,read thismanualcarefully tofamiliarize yourself
with the engine procedures involved, and the tools required. Keep this manual handy and refer to it often.
This manual is divided into 11 SECTIONS covering the topics listed on the CONTENTS page. At the
beginning of each
SECTION is an index of the subjects covered. Pages are numbered consecutively,
beginning with a new Page
1 at the outset of each SECTION. Each page number is preceded by the
appropriate reference number for that
SECTION. All illustrations are numbered consecur~vely,beginning
witha new Figure
1 in each SEC'TION.
Alwaysgivecomplete MODEL and SERIALNO. ofenginebeingserviced when ordering replacementparts.

Contents
SECTION AND TITLE
1. Specifications
2. Dimensions and Clearances
3. Torques
4. Special Tools
5. Troubleshooting
6. Start-Up
7. Maintenance
8. Oil System
9. Cooling System
10. Fuel System
11. Exhaust System
12. ElectricalSystem
13. Engine Disassembly
14. Turbocharger
!-GziGZl
INCORRECT SERVICE OR REPLACEMENT OF PARTS CAN RESULT IN
SEVERE PERSONAL lNJURY AND/OR EQUIPMENT DAMAGE. SERVICE
PERSONNEL MUST BE QUALIFIED TO PERFORM ELECTREAL AND/OR
MECHANICAL SERVICE.

1. Specifications
SUBJECT PAGE
ENGINE
.. ... ... .. ...... . . . ... . .. . ...... . . . .. . .... .. , . . . . .. ... . . . . . ... . -1-1
STATIC PUMPTlMlNG . . .. .. .. . .... .. . ..... .. .. . .. . . . . .. . . .. . .. . . . . . . . . -1-5

INDUSTRIAL ENGINE
UNITOF L SERIES
SPECIFICATION MEASURE L317 L423 L634 L634T
Number of Cyl~nders 3 4 6 6
Diesel Fuel ASTM2-D ASTM2-D ASTM2-0 ASTM2-D
Bore mm 89 89 89 89
(in) (3.50) (3.50) (3.50) (350)
Stroke mm 92 92 92 92
(in) (3.62) (3.62) (3.62) (3.62)
Displacement litre 1.7 2.3 3.4 3.4
(cuin) (105)
( 140) (210) (210)
Compression Ratio 21.5 to 1 21.5 to 1 21.5 to 1 21 5to1
Rated Speed (Maximum) RPM 3600 3600 3600 3600
Power (rntermrttent) at kW 31.3 43.3 65.0 85.8
Rated Speed' (BHP) (42.0) (58.0) (87.0) (115.0)
Power (continuous) at kW 28.5 39.4 59.1 78.0
RatedSpeed' (BHP) (38.0) (52.7) (79.1
) (1045)
Firing Order 132 1243 153624 153624
Crankshaft Rotation Counter
- Counter Counter Counter
(viewedfrom flywheel) Clockwise Clockwise Clockwise
Clockwise
Governor Variable Speed Mechan~cal Variable Speed Mechanical
Valve Lash(Spec
A to C) +
Intake mm 0.20 0.20 0.20 0.30
(in) (0.008) (0.008) (0.008) (0.01
2)
Exhaust mm 0.30 0.30 0.30 0.30
(in) (0.012) (0.012) (0.012) (0.012)
OilFilter FullFlow FullFlow FullFlow FullFlow
Crankcase Capacity litre 5.7
5.7
8.5 11.4
with filter change (qt) (6)
(6) (9) (12)
All dtmensions~nmetr~c (U S customary unitsof measure ~nparentheses) unlessotherw~sespecified
- Power obtained and corrected tn accordance with SAEJ1349 [I00 kPa (29 61 ~nchesHg)barometric pressureat 2S°C (77°F) alr tnlet
temperature] wtthout air cleaner.fan, and exhaust muffleron naturally
aspirated englnes
Power lossesfor typlcal air cleaner and muffler tnstallations ~ncludedon turbochargedengtnes
+ - Begtnn~ng Spec 0 no valve lash adjucmnerrt requtred.

MARINE ENGINE
UNITOF L SERIES
SPECIFICATION MEASURE
L317D-M L4230-M
Number of Cylinders 3 4
Diesel Fuel ASTM2-D ASTM2-D
Bore (in) (3.50) (3.50)
Stroke mm 92 92
Displacement litre 1.7 2.3
(cuin)
( 105) (140)
Compression Ratio 21.5 to
1 21.5 to 1
RatedSpeed (Maximum) RPM 3600 3600
Power (intermittent)at kW 32.4 44.7
RatedSpeed* (BHP) (43.5) (60.0)
Power (continuous) at kW 29.5 40.7
Rated Speed' (BHP) (39.5) (54.5)
FiringOrder 132 1243
Crankshaft Rotation Counter Counter
(viewedfrom flywheel) Clockwise Clockwise
Governor Variable Speed Mechanical
Valve Lash(Spec
A to C) +
Intake mm 0.20 0.20
(in) (0.008) (0.008)
Exhaust mm 0.30 0.30
(in)
(0 012) (0.012)
Oil Filter Full Flow Full Flow
Crankcase Capacity litre 5.7
5.7
with filter change
(9t) (6) (6)
Coolant Capacity litre
6.8 9.1
with heat exchanger (qt) (7.2)
(9.6)
All dimensionsin metric (US. customaryunitsof measurein parentheses) unlessotherwisespecified.
- Power obtained with 100 kPa (29 .92 inchw Hg) barometric pressureat 1S0C (60°F) air inlet
temperature without air cleaner or exhaust muffler.
+ - Beg~nntng Spec D no valve lash adjustment required.