Onan BF Series Instruction Manual

®
OPERATOR'S/SERVIwi
MANUAL
AND PARTSCATALOG
FOR
BF
SERIES
180AMP.AC WELDER
MODELS
5.0 BF-341E/*
5.0 BF-343E/*
•SPECIFICATIONS5277AAND8474A
965-1003
9A73
Printed inU.S.A.

180AMP. WELDER
BF
SERIES
RANTY CARD ATTACHED TO UNIT.
KEEPTHISMANUALHANDYSOITCANBEEASILYREFERREDTOWHENORDERING
PARTS, MAKINGADJUSTMENTS,ETC.

GENERAL INFORMATION
TheBFwelderisa completeenginedriven,alter-
natingcurrentarcweldingmachine.Itconsistsofa
two-cylindergasolineenginedirectlyconnectedto
anelectricgeneratorandmountedtoa sturdy
carryingframe.TheweldercontrolsandACoutput
receptaclesarelocatedinthecontrolboxthatis
mountedonthegeneratorendoftheunit.Anoptional
two-wheeleddollyisavailableiftheunitmustbe
movedfrequently.
WARNING Thissymbolisusedthroughoutthemanualto
warnofpossiblepersonalinjury.
[CAUTIONj Th'ssymbolreferstopossibleunitdamage.
Thewelderisrated180amperes,25volts,alternating
currentat50%dutycycle.Auxiliaryalternating
currentisavailableandoutputis120voltsor120/240
volts, rated5000watts,60hertzat100%dutycycle.
ACoutputisavailableatanytimealthoughatreduced
outputwhentheweldingcurrentisbeingused.This
ACoutputisconvenientforemergencylighting,
runningpowertools,etc.,whenworkingatlocations
awayfromACpowerlinesources.
Wheninstructionsinthismanualrefertoa specific
modelofwelder,identifythemodelbyreferringtothe
modelandspecificationdesignationasshownonthe
unitnameplate.
Howtointerpretmodelandspecificationnumber.
Beforeoperatinganywelder,becomethoroughly
familiarwiththesafetyprecautionsthatfollow!
5.0BF- 341E / 1 A
45
1. IndicatesKilowattratingandfactorycodefor
generalidentification.
2. FactorycodeforACvoltageoutput:code341
indicates120volts,AC;343indicates120/240
volts, AC.
3.Specifictype:E- Electricstartingatwelderonly.
4. Factorycodeforoptionalequipmentsupplied.
5.Specificationletteradvanceswithfactory
productionmodification.

SAFETY PRECAUTIONS
ALWAYS EMPLOY PRECAUTIONARY MEASURES
DURINGARCWELDING OPERATIONS TOEN-
SURE MAXIMUM PERSONAL SAFETY ANDTHE
SAFETY OF NEARBY PERSONNEL.
OperateAnd Maintain TheMachineAndIts
EquipmentProperly.
Donotoverloadthecables.Donotusewornor
poorlyconnectedcables.Donotallowthe
weldingcablestocontacthotmetal,water,oilor
grease.Preventcablesfrombecominga stumbl-
inghazardbykeepingtheminorderandoutofthe
way.
Useelectrodeholdersthatarecompletelyin-
sulated. Donotuseholderswithdefectivejaws.
Donotusethewelderwithoutgroundingthe
frameorthecase.Donotgroundtopipelines
carryinggasesofflammableliquids.Besurethe
conductorscansafelycarrythegrounding
current.
Keepallconnectionscleanandtight.
Donotuseanelectricwelderonanengineunless
boththeengine'sbatterycablesandalternator
wiresaredisconnected.
Take PrecautionsAgainst Electric Shock.
NEVERworkina dampareawithoutsuitable
insulationagainstshock.
NEVERstandinwaterorona wetfloororusewet
gloveswhenwelding.
ALWAYSdryouttheworkpiecesorbenchifthere
isanyevidenceofmoisture.
OPENpowercircuitsbeforeinspecting
machines.
ALWAYSturnoffthemachinewhenleavingthe
work.
*DoNotWeldNearInflammableMaterials.
NEVERweldinornearEXPLOSIVEAT-
MOSPHERES.
Cleananycontainerthathasheldcombustibleor
flammablematerialsbyapprovedorprescribed
methods.A verysmallamountofresidualgasor
liquidcancausea seriousexplosion.Whenthe
contentsofthecontainerisunknown,usean
explosimeter.
Usecarbondioxideornitrogentoventilatea
container.NEVERUSEOXYGEN.
Whenthecontainerhashelda gasorliquidthat
readilydissolvesinwater,performthefollowing:
1. Flushthecontainerseveraltimeswithwater
anda wettingagent (e.g., a lowpowered
detergent).Then,fillwithasmuchwaterasthe
workpermits.
2. Providea ventoropeninginthecontainerto
allowthereleaseofairpressure.
Whenthecontainerhashelda gasorliquidthat
doesnotreadilydissolveinwater,proceedas
follows:
1. Cleanthecontainerwithsteamora cleaning
agentandpurgeallairwitha gassuchascarbon
dioxideornitrogen.
2. Usesteamtocleanoutlightmaterial.
3.Tocleanoutheavygreaseoroil,usea strong
causticsodasolution.
4. Beforeweldingonthecontainer,PURGEALL
AIRwithagassuchascarbondioxideornitrogen.
Weargogglesandgloveswhencleaningwith
steamorcausticsoda.
Alwayscleanthecontainerina wellventilated
area, awayfromanyopenflame.
Whenscrapingorhammeringheavysludgeor
scale, usea WET,sparkresistant tool.
Alwayskeepheadandarmsasfarawayfromthe
workaspossible.
•NeverWeldOnHollow(Cored) Castings That
HaveNot Been ProperlyVented.
•Never Pick UpHot Metal With Bare Hands.
•DoNotWeldInConfined Areas Without Adequate
Ventilation.

NeverWear Frayed, FlammableOrOtherwise
InadequateClothingWhenWelding. Keep
ClothingDry.
Avoidwearinglightcoloredoropenshirtsthat
allowarcraystopenetrateandexposeparts'ofthe
bodytoultra-violetrays.Donotwearflammable
cottonfabricswhenarcwelding.Wearheavy
shoes,tightlylaced.
Topreventsevereburnsfromsplatterandmolten
metal, wearleatherorasbestosglovesatall
timesprotectingthehandsandwrists.When
weldinginverticalandoverheadpositions,wear
earshieldsunderhelmetandleathersleevelets,
apron, andleggings.
Use EyeProtectionAtAll Times.
ALWAYSwearsafetygogglesunderthewelding
helmet.Keepthehelmet,handshields,andface
shieldingoodcondition.Replacedefective
equipment.
Allarcweldingproducesintenseultra-violetand
infra-redradiation.Whenweldinginopenareas,
provideportablenon-reflectingscreensto
protectnearbypersonnelfromarcrays.

SPECIFICATIONS
NominalDimensions
Height29-1/2"
Width: : 22"
Length: 34"
WeightinPounds(approx.)
Skidmounted,electric....325
Fuel"Gasoline
NumberofCylinders•.2
CylinderBore: 3-1/8"
CylinderStroke2-5/8"
Displacement(cu.in.)40.3
MaximumBHP(at3600rpm)16
GovernorAdjustable,mechanicalflyball
FuelPumpPulseDesign
Ignition, ElectricStartBattery
MountedFuelTankCapacity(U.S.gallons)5.6
OilCapacity(U.S.quarts)2
Generator
WelderOutput- MaximumAmperes(50%dutycycle)180
ACAuxiliaryWattsOutput(120or120/240volts,
single-phase,100%dutycycle)5000
BatterySize
NominalBatteryVoltage12
NumberUsedOne
Ampere/HourSAE20Hr.Minimum32
Approx.BatteryDimensionsforBatteryRack7-3/4"L x 5-1/8"W x 7-3/8"H
*- Non-leadedorregulargrade.See OPERATIONsectionforspecialinstructions.
TUNE-UP SPECIFICATIONS
Tappets(Cold)Intakei 008*
Exhaust013*
BreakerPointGap(FullSeparation)025
SparkPlugGap.025
IgnitionTiming(EngineRunningorStatic)21°BTC(HOT)
25°BTC(COLD)
*- ± .001"

threads.Ifa torquewrenchisnotavailable,estimate
thedegreeoftightnessnecessaryforthe stud, nutor0ther5/16"CylinderBlock
screwbeinginstalledandtightenaccordingly.Donot
DIMENSIONSAND CLEARANCES
Alldimensionsandclearancesgivenatroomtemperatureof70°F.
Allvaluesininchesunlessotherwisespecified.
MinimumMaximum,
CAMSHAFTANDCRANKSHAFT
CrankshaftMainBearingJournaltoBearingClearance0.00250.00381
*CrankshaftEndPlay0.0060.012
CamshaftBearingtoCamshaft0.00150.0030
CamshaftEndPlay0.003
*CrankshaftRodJournaltoRodBearing0.00200.0033
ConnectingRodEndPlay0.0020.016'
TimingGearBacklash0.0020.003'
OilPumpGearBacklash0.0020.005
PISTONANDCYLINDER
PistonPininPiston0.00020.0004
PistonPininRod0.00020.0007
*PistonRingGapinCylinderr 0.0100.020
PistonClearanceinCylinder- Measured.10BelowOil
ControlRing,90°fromPin0.0010.003-
CylinderBore- StandardSize3.12453.1255'
CrankshaftMainBearingJournal- StandardSize 1.9992 2.0000
CrankshaftRodBearingJournal- StandardSize 1.6252 1.6260
TAPPETSANDVALVES
*ValveSeatWidth1/321/8
*ValveFaceAngle44°
*ValveSeatAngle45°
ValveStemtoGuide- Intake0.00100.0025
ValveStemtoGuide- Exhaust0.00350.0040
TappettoCylinderBlockClearance0.00150.0030
TappetAdjustment(Cold)
*Intake0.0070.009
*Exhaust0.0120.014
*- Frequentlyusedoverhaulvalues.
ASSEMBLY TORQUES
BOLTTORQUEFT.- LB.
GearcaseCover8-10
AOOCMDI v -rrmoiiccCylinderHeadStudNuts(Cold)14-16
ASSEMBLYTORQUESRearBearingp|ateScrews25_ 27
Assembly torques as given here require the use of a StarterMountingBo|ts18. 2Q
torquewrench.TheseassemblytorquesassureConnectinaRodBolt14-16
propertightnesswithoutdangerofstrippingtheconnectingHodBolt1416
FlywheelCapScrew35-40
StudandNuts8-10
stripthethreads.Checkallstuds,nutsandscrewsOilBase18-23
often. TightenasneededtopreventthemfromManifoldMountingStudNuts6-9
workingloose.OilPump7-9

INSTALLATION
Normally,theBFwelderisnotpermanentlymounted;
thusnoinstallationinstructionsarenecessary.
However,ifthewelderistobeusedina permanent
locationormountedina vehicle,usethefollowing
recommendationsasa guide.
VENTILATION
Weldersgenerateconsiderableheatduringopera-
tion. Therefore,whenoperatinginanysmall
enclosure,provideseparate,unobstructedairinlet
andoutletopenings(minimumareaof3-1/2square
feeteach).Positiontheopeningstopreventrecircula-
tionofheatedair:
•Locatetheinletopeningascloseaspossibleto
thefrontoftheengineblower.
•Provideanoutletopeningtowardthegenerator
end, somewhathigherthantheinletopening.
EXHAUST
Whenmountingextensionexhaustpipestothe
engine,usea pieceofflexibletubingbetweenthe
extensionsandtheengine.Fitthemufflerstothe
outerendoftheexhaustpipes.
WARNING EngineexhaustcanbedeadlylNeveroperate
thewelderinsidea buildingorconfinedarea
withoutpipingexhaustgasesoutsidetheenclosure.
MOBILE MOUNTING
Installingthewelderina vehiclerequiresspecial
attention. Roughroadsandsharpcornersproduce
considerablestrainontheweldermountingbolts.
Extravehiclefloorsupportmaybenecessaryto
preventtheboltsfromdisengaging.Usepipeclamps
oru-boltswhensecuringthewelderframetothe
floor.
Theweldercanoperateatamaximumtiltof15°sideways,30°front
torear.

OPERATION
PRE-START INFORMATION
Whentheunitistobeusedforwelding,always
connecttheweldingcablestothepowerterminalson
thepanelbeforestarting.Itisnotnecessaryto
observepolarityinmakinggroundconnections
betweenwelderandthework.Weldingcurrentselec-
tionmaybemadewiththeunitrunningbutnotunder
load.
IWARNINGI Donot'underanycircumstances,touchthe
Iw^^^^^^^Jterminalsofthewelderwhileitisoperating!
Althoughthevoltageisnothigh,itcancausesevereshockwith
possibleseriousconsequences!Stoptheunitbeforemaking
connections.
ELECTRIC STARTING:
1. Adjustchokeaccordingtotemperature con-
ditions.
2. Move ignition switch to ON.
3.PushSTARTswitch,locatedonrearsideof
controlbox,firmly.Ifunitdoesnotstartwithina
fewseconds,releasethe57>4^?rswitchandwaita
fewsecondsbeforereattemptingtostart.Ifunit
doesnotstartaftertwoattempts,openthechoke
andrepeatstartingsequence.
4. Afterunitstarts,adjustchoketobestrunning
position. Graduallyadjustchokecontrolasunit
warmsup.
INITIAL START
Checktheenginetomakesureithasbeenfilledwith
oiland fuel. Seetherecommendationsbelow.
CRANKCASE OIL:
BesurethecrankcasehasbeenfilledtotheFULL
markwithanAmericanPetroleumInstitute(API)
designationSEoiloftheviscosityrecommendedon
thenameplate.IftheSEoilisnotavailable,anSDor
SD/CCoilmaybeused.SeePERIODIC
MAINTENANCEsectionforcompletelubrication
recommendations.
Ifoilswiththesedesignationsarenotyetavailable,useanoilwith
theAPIdesignationMS,MS/DGorMS/DMwhichhaspassedall
theAutomotiveManufacturer'sSequenceTestsandtheMIL-L-
2104BTests.DonotuseanoilwiththeAPIdesignationMLorDS.
RecommendedFuel:Useclean,fresh,regulargrade,
automotivegasoline.Donotusehighlyleaded
premium fuel.
Fornewengines,themostsatisfactoryresultsare
obtainedbyusingnonleadedgasoline.Forolder
enginesthathavepreviouslyusedleadedgasoline,
headsmustbetakenoffandallleaddepositsremoved
fromenginebeforeswitchingtononleadedgasoline.
CAUTION Ifleaddepositsarenotremovedfromengine
beforeswitchingfromleadedtononleaded
gasoline,preignitioncouldoccurcausingseveredamagetothe
engine.
WARNINGI Neveraddfueltowelderwhileitisrunning.
Thebatterychargevoltageisregulatedtosupplyanominal 1 .Samp
chargeratealfullrpm.
APPLYING LOAD
Allowtheenginetowarmupthoroughlyatidlespeed
beforeapplyinga heavywelding load. Settheidle
leveratweldpositionbeforeapplyinga load. The
welderisthermallyprotectedandself-regulating.
Althoughtheweldercanbeloadedtofullnameplate
ratingforinitialoperation,itisrecommendeditbe
loadedonly80%ofratedcapacityforfirstfewhours.
Controlledbreak-inwiththeproperoilanda con-
scientiouslyappliedmaintenanceprogramhelps
assuresatisfactorywelderserviceforhundredsof
hours.
After25hoursofoperation,draintheinitialoilwhiletheengineis
stillhot.
STOPPING
MoveignitionswitchtoSTOPorOFFposition.If
ignitionswitchisleftintheOppositionwhenunitis
notrunning,batterywilldischarge.
WELDING CURRENT CONTROL
Thecontrolpanelcontainsa currentselectorhandle
thatcanbeturnedtoanyoneofthedialpositionsfor
therequiredweldingamperage(Figure1).Makesure
thehandlesnapsfirmlyintoplacewhenmakingthe
desiredamperageselection.Onsomemodels,an
optionalrheostatisprovidedforfinecurrentcontrol.
CAUTION
Oncoldstarts,settheidleleverintheidlepositiontotherightto
start.Theidleleverislocatedadjacenttothegovernoryokecontrol
shaft.Setmanualchokeasnecessaryforweatherconditions.
Considerableheatisgeneratedbythereactor
assemblyinsidetheweldercontrolbox.
Alwayskeepmeengineandcontrolcoverinstalledontheunitto
properiydirectairtothecontrolbox.NEVERWELDWITHTHE
ENGINEANDCONTROLCOVERREMOVED.

130v.nov.• «isn r
FIGURE1.CONTROLPANEL
WELDING CABLE SIZE
Keeptheweldingcablesasshortaspossible.Check
allconnectionsfortightness.Table1 listsJhecable
sizeforcurrentdrawandcablelength.
Whenweldingwithlongcables,avoidallowingthe
cablestoformcoils.A coilofcableproducesa
magneticfieldthatcanlowerthegeneratoroutput.If
youhaveexcesscableonthefloor,tapethecables
togetheratshortintervalsandarrangethemin
"snake"fashiontotakeuptheslack.
CAUTION Donotchangetheamperagetap(control
handle)whilethepowerisbeingusedfor
weldingorpipethawing.Thesuddenconnectionbreakcan
produceanarcwithinthecontrolboxandcauseseriousdamageto
theswitchingmembersorothercomponentsinthecontrolcircuit.
AUXILIARY AC POWER
Theweldersareavailablewitheither120-voltAC,
5KWauxiliarypoweror120/240-voltAC,5KWaux-
iliarypower.The120-voltmodelisequippedwithtwo
120-voltduplexreceptacleswitheachoutlet(4)rated
at 1 Samps. Althougha totalof42ampsisavailable,no
morethan15ampsmaybedrawnfromanyindividual
outlet.
Thethreeoutletsofthe120/240-voltmodelarerated
at20ampereseach.Drawnomorethan20ampsfrom
anyindividualoutlet.
TABLE1.RECOMMENDEDWELDINGCABLESIZE
ACPOWER
AMPERES TOTALCIRCUITLENGTHINFEETACPOWER AMPERES 100 150 200 250 300 400
75 6 4 3 3 2 1
100 4 3 3 2 1 1/0
150 3 2 1 1/0 2/0 3/0
200 2 1 1/0 2/0 3/0 4/0
Useofauxiliarypowerisnotrecommendedwhile
weldingcurrentisbeingused.Ifnecessary,however,
alowwattagetroublelightmaybeconnectedwithout
unduelossofweldingpower.Thegovernorcontrol
levermustbeintheWELDpositionforbothweldand
auxiliarypower.Onmodelswiththeoptionalrheostat
forfinecurrent,turnpointerknobtothe"10& AC"
position.
Usingauxiliarypowerduringweldingoperationcausesa voltage
dropwhenthearcisstruckandduringactualwelding.

OUT-OF-SERVICE PROTECTION
Protectanenginethatistobeout-of-serviceformore
than30daysasfollows:
1. Runengineuntilthoroughlywarm.
2. Turnofffuelsupplyandrununtilenginestops.
3.Drainoilfromoilbasewhilestillwarm.Refilland
attacha warningtagstatingoilviscosityused.
4. Removesparkplugs.Pourlounce(two
tablespoons)ofrustinhibitor(orSAE50oil)into
eachcylinder.Crankengineovera fewtimes.
Reinstallsparkplugs.
5.Serviceaircleaner.
6.
7.
Cleangovernorlinkageandprotectbywrapping
witha cleancloth.
Plugexhaustoutletstoprevententranceof
moisture,dirt,bugs,etc.
8. Wipeentireunit.Coatrustablepartswitha light
filmofgreaseoroil.
9.Disconnectthebatteryandfollowstandard
batterystorageprocedure.
Providea suitablecoverfortheentireunit.
10
HIGHAMBIENT TEMPERATURES
1. Seethatnothingobstructsairflowtoandfromthe
plant.
2. Keepcoolingfinsclean.Airhousingshouldbe
properlyinstalledandundamaged.
LOW AMBIENT TEMPERATURES
1. UsecorrectSAEoilforexistingtemperature
conditions.Changeoilonlywhenengineiswarm.
Ifanunexpectedtemperaturedropcausesan
emergency,movetheunittoa warmlocationor
applyexternalheatuntiloilflowsfreely.
2. Usefresh fuel. Protectagainstmoistureconden-
sation.
3.Keepfuelsystemcleanandbatteriesina well
chargedcondition.
EXTREMELY DIRTY OPERATING CON-
DITIONS
1. Keepunitclean.Keepcoolingsystemclean.
2. Serviceaircleanerasfrequentlyasnecessary.
3.Changecrankcaseoilevery40operatinghours.
4. Keepoilandgasolineindust-tightcontainers.
5.Keepgovernorlinkageclean.
HIGH ALTITUDE
Foroperationataltitudesover2500feetabovesea
level, closecarburetormainjetadjustmentslightlyto
maintainproperair-to-fuelratio(refertoFUEL
SYSTEMsection).Maximumpowerwillbereduced
approximately4 percentforeach1000feetabovesea
levelafterthefirst1000feet.
10

ENGINETROUBLESHOOTING
STARTINGSYSTEM
• • LooseorCorrodedBatteryConnection
• • LoworDischargedBattery
• • FaultyStarter
• FaultyStartSolenoid
• a • • • • IgnitionTimingWrong,
• • • WrongSparkPlugGap
• u • WornPointsorImproperGapSetting
n • BadIgnitionCoilorCondenser
a • FaultySparkPlugWires
-
IIBHi^^i^^B^Illlll!
FUELSYSTEM
• • OutofFuel- Check
• • • • • • LeanFuelMixture- Readiust
t • • • • RichFuelMixtureorChokeStuck
a • • • EngineFlooded
• • • • • PoorQualityFuel
• • • • DirtyCarburetor
• • • • • • • • DirtyAirCleaner
• • • DirtyFuelFilter
• • • • DefectiveFuelPump
INTERNALENGINE
• • • • • WrongValveClearance
• • • • • • BrokenValveSpring
• • • • • ValveorValveSealLeaking
• • • • PistonRingsWornorBroken
• • • • • WrongBearingClearance
COOLINGSYSTEM(AIRCOOLED)
• • PoorAirCirculation
• • DirtyorOilyCoolingFins
• • • • BlownHeadGasket
COOLINGSYSTEM(WATERCOOLED)
• InsufficientCoolant
•
FaultyThermostat
• WornWaterPumoorPumoSeal
• WaterPassagesRestricted
• DefectiveGaskets
• • • • • • BlownHeadGasket
LUBRICATIONSYSTEM
• • DefectiveOilGauge
• • ReliefValveStuck
• • • • • • • FaultyOilPump
• • • • • • DirtyOilorFilter
• • • • • • • • • • OilTooLightorDiluted
• • • • • • • • OilLevelLow
• • OilTooHeavy
• * • • DirtyCrankcaseBreatherValve
THROTTLEANDGOVERNOR
• • LinkageOutofAdjustment
• LinkageWomorDisconnected
• GovernorSpringSensitivityTooGreat
• LinkageBinding
<9
11

PERIODIC MAINTENANCE
AIR CLEANER
Ifaircleanerbecomestoodirty,enginewillnotreceivesufficientair
torunproperly.Symptoms:Lossofpower,flooding,hardstarting
andoverheating.
TheBFengineisequippedwitha paperelementanda
polyurethanepre-cleanerthatmustberemoved,
cleanedandoiledevery25hoursofoperation,or
moreoftenunderextremelydustyconditions.
2. Dependingonconditionsinwhichthewelderis
operating, theinnerpaperelementshouldbe
replacedwheneveritbecomesexcessivelydirty.
CAUTION Neverruntheenginewiththeaircleaner
removed. Dirtwillentertheengineandscore
thecylinders.
1. Tocleanpolyurethanepre-cleaner,washinwater
anddetergent.Removeexcesswaterbysqueez-
inglikea spongeandallowtodrythoroughly.
DistributethreetablespoonsofSAE30engineoil
evenlyaroundthepre-cleaner.Kneadintopre-
cleanerandwringoutexcessoil.
CRANKCASEBREATHER*
Thecrankcasebreathervalvemaintainscrankcase
vacuum. Nomaintenanceisgenerallyrequired.Ifthe
crankcasebecomespressurizedasevidencedbyoil
leaksattheseals,cleanbaffleandvalveina suitable
solvent(Figure2).
WINSNUT
COVER
PAPER
ELEMENT
XPOLYURETHANE
PRE-CLEANER
BASE
1. WASH
2. SQUEEZEDRY
3.COATWITHOIL
4. INSTALLOVERPAPERELEMENT
FIGURE2.AIRCLEANERASSEMBLY
.12

BREATHERHOSE-
ACORN/ \.
NUT^cr~<il
FLAT
WASHER
VALVEBOX
COVER
GASKET
REEDVALVE
BREATHERBAFFLE
GASKET
FIGURE4.OILDRAINLOCATION
FIGURE3.CRANKCASEBREATHER
CRANKCASE OIL
Changecrankcaseoilevery50operatinghoursand
onlywhentheengineiswarm.(Exception:Draininitial
oilfillat25operatinghours.)
Todrain,removethe 1/2-inch pipecaponthesideof
theoilbase(Figure4).Afteroildrains,replacethe
pipecapandrefillcrankcasewith4 pints(4-1/2if
equippedwithfilter)ofa goodqualitydetergentoil.
OilmustmeetorexceedtheAPI(American
PetroleumInstitute)designationSEorSE/CC;thisoil
wasformerlydesignated2SMS,MS/DGorMS/DM.
Fortemperaturesabove30°F,useSAE30oil;for
temperaturesbelow30°F,use5W30or10W.
Inextremelydustyconditionsorinverycoldweather,
changeoilatleastevery25hoursofoperation.
CoolingSystem:Checkandcleancoolingfinsatleast
every50hours.Removeanydust,dirtoroilwhich
mayhaveaccumulated.
CAUTION Pluggedorcloggedcoolingfinscancause
overheatingandenginedamage.
CAUTION Donotoverfillcrankcase.Donotuseservice
DSoil.Donotmixbrandsnorgradesofmotor
oil.
SparkPlugs:Check,cleanandresetsparkplugs
every100operatinghours.Replacesparkplugsthat
showsignsoffoulingorelectrodeerosion.
13

PERIODIC MAINTENANCE SCHEDULE
Regularlyscheduledmaintenancelowersoperatingcostsandlengthenstheservicelifeofthewelder.Usethe
followingscheduleasa guide.
However,actualoperatingconditionsunderwhicha unitoperatesshouldbethedeterminingfactorin
establishinga maintenanceschedule.Whenoperatinginverydustyordirtyconditions,someoftheservice
periodsmayhavetobereduced.Checktheconditionofthecrankcaseoil,thefilters,etc.,frequentlyuntilthe
properservicetimeperiodscanbeestablished.j
Foranyabnormalitiesinoperation,unusualnoisesfromengineoraccessories,lossofpower,overheating,'
etc.,contactyournearestOnanServiceCenter.
SERVICETHESE ITEMS
AFTEREACHCYCLE OFINDICATED HOURS
SERVICETHESE ITEMS 8 50 100 200 400 1000
InspectOverallEngine
X
CheckOilLevel x
ServiceAirCleaner xl
ChangeCrankcaseOil xl
CheckBatteryElectrolyteLevel
X
CheckSparkPlugs
X
CleanBreatherValve
X
CheckBreakerPoints
X
CleanFuelSystem
X
ReplaceAirCleanerElement xl
RemoveCarbonandLeadDeposits x2
CheckValveClearance x2
InspectValves,GrindIfNecessary x2
CompleteReconditioning(IfRequired) x2
xl- Performmoreofteninextremelydustyconditions.
x2- Fordetailedmaintenance,contactanOnanServiceCenter.
14

ADJUSTMENTS
CARBURETOR
Thecarburetorhasa mainfuel(highspeed)adjust-
mentandanidlefueladjustment.Themainadjust-
mentaffectsoperationunderheavyloadconditions
(Figure5).Idleadjustmentaffectsoperationunder
lightornoloadconditions.Undernormalcir-
cumstances,factorycarburetoradjustmentsshould
notbedisturbed.Iftheadjustmentshavebeen
disturbed, turnneedlesofftheirseats,1to1-1/4turn
topermitstarting.Then,readjustthemforsmooth
operation.
Damagewillresultiftheneedleisforced
againstitsseat.Theneedledoesnotcom-
pletelyshutofffuelwhentumedfullyin.
BREAKER POINTS(ColdSetting)
Tomaintainmaximumengineefficiency,changethe
breakerpointsevery200hoursofoperation.Proceed
asfollowswhentheengineis cold:
1. Removethefourscrewsandcoverofthecontrol
box.
2. Disconnectthewireleadthatrunsfromthe
controlboxtotheignition coil.
3.RemovethesevenfastenersasshowninFigure6,
thenremovethefrontpanel.
4. Loosenbothscrewsholdingtheliftingeye.Then,
removeoneofthescrewsandswingliftingeye
outofthewaytogainaccesstothebreakerbox.
Beforefinaladjustment,allowtheenginetoreach
normaloperatingtemperature.Maketheidleadjust-
mentunderno load. Openthemainjetuntilthe
enginerunssmoothunderaccelerationwithno load.
Slightlymorefuelmaybeneededwhensuddenload
isapplied(openabout1/4tumfurther).
Setthethrottlestopscrew(locatedoncarburetor
throttlelever)withnoloadconnectedandwhile
runningata lowspeedsetting.Turnthescrewtogive
approximately 1/32-inch clearancebetweenthe
screwandpin.
Iftheenginedevelopsa "hunting"condition(alter-
nateincreaseanddecreaseofenginespeed),try
correctingbyopeningthemainadjustingneedlea
littleTnore.Donotopenmorethan1/2turnbeyond
themaxifrrumpointofpower.
LOWSPEEDSET
ONGOVERNOR
LINKAGE-SMALL
GAPHEREATNO
LOAD„|
THROTTLE
STOP
SCREW
SIDEVIEW
MAINFUEL
(HIGHSPEED)
ADJUSTMENT
IDLE
ADJUSTMENT
REARVIEW
ii i'/Mm a/ ///,
FIGURE6.REMOVINGFASTENERS
5.Removethetwoscrewsandthecoveronthe
breakerbox.
6.
7.
FIGURE5.CARBURETORADJUSTMENT
Removethetwosparkplugssoenginecrankshaft
canbeeasilyrotatedbyhand.Checkconditionof
sparkplugsatthistime.
Removemountingnut(A)andpullthepointsout
oftheboxjustfarenoughsoscrew(B)canbe
removedandtheleadsdisconnected.SeeFigure
7.
15

FIGURE7.BREAKERPOINTSETTING
Thedesignofthegovernorgivesanautomatic
decreaseinsensitivitywhenthespeedisincreased
resultingingoodstabilityatbothspeeds.
Beforemakinggovernoradjustments,runtheengine
about15minutestoreachnormaloperating
temperature.Iftheengineisbeingrunwiththe
throttlewideopen,eitherthegovernorisnotproperly
adjustedortheengineisoverloaded.Itisdifficultto
determineifafterlongusagethegovernorspringhas
becomefatigued.Afterproperlymakingallother
adjustments,iftheregulationisstillerratic,installa
newspring.
Usea tachometerasa reliableinstrumentforcheck-
ingenginespeedwhenmakinggovernoradjustment.
8. Removescrew(C)andreplacecondenserwitha
newone.
9.Replacepointswitha newsetbutdonotcom-
pletelytightenmountingnut(A).
10. Rotatetheenginecrankshaftclockwise(facing
flywheel)byhanduntilthe25°BTCmarkonthe
blowerhousingalignswithmarkontheflywheel.
Turnanother1/4turn(90°)toensurepointsare
fullyopen."
11. Usinga screwdriverinsertedinnotch(D)onthe
rightsideofthepoints,turnthepointsuntilthe
gapmeasures.025"witha flatthicknessgauge.
(Besurefeelerisclean.)Tightenmountingnut
andrecheckgap.(Seenote.)
12. Reassemblecontrolbox.
Note: Analtematemethodofsettingthepointsistousea continuity
lightandadjustthepointstobeginseparatingat25°BTC(engine
cold)or21°BTC(enginehot).
Checkthegovernorarm,linkage,throttleshaft,and
leverfora bindingconditionorexcessiveslackand
wearatconnectingpoints.A bindingconditionatany
pointcausesthegovernortoreactslowlyand
producepoorregulation.Excessiveloosenesscauses
ahuntingconditionanderraticregulation.Workthe
armbackandforthmanuallyseveraltimeswiththe
engineinidle.Ifeitheroftheseconditionsexists
determinethetroubleandadjustorreplacepartsas
needed.
Linkage:Theenginestartsatwideopenthrottle.The
lengthofthelinkageconnectingthegovernorarmto
thethrottlearmisadjustedbyrotatingtheballjoint.
Adjustlengthsothatwiththeenginestoppedand
tensiononthegovernorspring,thelowerstoponthe
carburetorthrottleleveris1/32"fromthestoppin.
Thissettingallowsimmediatecontrolbythegovernor
afterstartingandsynchronizestravelofthegovernor
armandthethrottleshaft.
GOVERNOR ADJUSTMENT
Enginespeedisgovernor-controlledandpresetatthe
factory.Propergovernoradjustmentisoneofthe
mostimportantfactorsinmaintainingthepowerand
speeddesiredfromtheengine.
Theseenginesareadaptedforusewherea double
rangeofspeedsettingsisdesired.Enginespeedis
controlledatidle(approximately2200to2300RPM)
andmaximum(approximately3600RPM)bysimply
shiftingthegovernorcontrolleverupforhighspeed
anddownforidle(Figure8).
Procedure:Thisgivestheprocedureonlybriefly.
Refertothedetailsoneachsubjectherein.
1. Adjustthecarburetormainjetforthebestfuel
mixtureatfullloadoperation.
2. Adjustthecarburetoridleneedlewithnoload
connected.
3.Adjustthelengthofthegovernorlinkage.
4. Checkthegovernorlinkageandthrottleshaftfor
bindingorexcessivelooseness.
5.Adjustthegovernorspringtensionfornominal
enginespeedatno-loadoperation.
6.Checktherpmdropbetweenno-loadand full-
loadoperationandadjustthegovernorsensitivity
asneeded.
7.Recheckthespeedadjustment.
8. Setthecarburetorthrottlestopscrew.
16

THIS
DISTANCE
DETERMINES
SENSITIVITY
GOVERNOR
SPRING
LEVER
FIGURE 8.GOVERNORADJUSTMENTS
Approximately3600 rpmisthe recommendedmax-
imumfullloadspeed for continuousoperation. The
speedmustagreewith the loadrequirements.
If a speedadjustment is needed,turn the speed
adjusting nutinto increase the speed oroutto
decrease the speed.
SpeedAdjustment: The speed at which the engine
operates is determined bythe tensionapplied tothe
governorspring.Increasingspringtensionincreases
enginespeed;decreasingspringtensiondecreases
enginespeed. The no-loadspeed ofthe engine
shouldbeslightlyhigherthanthespeedrequirements
of the connected load.
Thesensitivity ofthe governordepends onthe
position ofthearmendofthe governorspring. A
threadedstud onthe governor arm provides for
adjustment. To increasesensitivity,move the gover-
norspringtoward the governorshaft by turning the
screw in;to decreasesensitivity,move the governor
springawayfrom the governorshaft by turning the
screw out.
17

OPERATOR MAINTENANCE SCHEDULE
CRITICAL MAINTENANCE SCHEDULE
MAINTENANCE
ITEMS
OPERATIONAL HOURS MAINTENANCE
ITEMS 8 50 100 200
InspectWelder X
CheckBreakerPoints X
CheckOilLevel X
CleanAirCleaner xl
CleanGovernorLinkage xl
CheckSparkPlugs X
ChangeCrankcaseOil X
CleanCrankcaseBreather X
CleanFuelSystem X
CheckBattery X
xl- Performmoreofteninextremelydustyconditions.
MAINTENANCE
ITEMS
OPERATIONAL HOURS
MAINTENANCE
ITEMS 200 500 1000
CheckCollectorRings xl
CheckBrushes x2
RemoveCarbon& Lead x3
CheckValveClearance X
CleanCarburetor X
CleanGenerator X
GrindValves(ifrequired) X
GeneralOverhaul(ifrequired) X
xl- Performmoreofteninextremelydustyconditions.
x2- Replacebrusheswhenwornto5/16"orless.
x3- Thefrequencyofcarbonorleaddepositremovalwillvary
withoperatingconditions.Frequentshortoperating
periods,consistentlycooloperation,useofhighlyleaded
gasoline,etc.aresomecausesofmorerapidformationsof
combustiondeposits.Removedepositsasexperience
indicatesthenecessity.Alwaysinstallnewgaskets.
Foranyabnormalitiesinoperation,unusualnoisesfrom
engineorgenerator,lossofpower,overheating,etc.,
contactyourdealer.
18

FUEL SYSTEM
CARBURETOR CLEANING AND INSPEC-
TION
Toclean the carburetor,soak all components
thoroughly ina goodcarburetorcleaner,following
themanufacturer'sinstructions.Besuretoremoveall
carbonfromcarburetorbore,especiallyintheareaof
thethrottlevalve.Aftersoaking,clean outall
passageswithfiltered,compressed air.
Check the adjustingneedlesandnozzle for damage.
If the float is loadedwithfuel or damaged,replace it.
Thefloatshould fit freely onitspin withoutbinding.
Checkthechokeand th rottleshaftsforexcessiveside
playandreplace if necessary.
Carburetorrepairandgasketkitsareavailablefromyournearest
OnanPartsCenter.
CHOKE FLY
CHOKESHAfT
ANDLEVER
NOTE
ONSOMEMODELSENGINESFUEL
PUMP IS MOUNTEDDIRECTLY TO
CARBURETOR.
—SLEEVE
ASSEMBLY
FLOATVALVE
ASSEMBLY
FLOAT AND LEVER
ASSEMBLY
MAINADJUSTING
NEEDLE
IDLEADJUSTING
NEEDLE
THROTTLESTOPSCREW
THROTTLESHAFT
ANDLEVER
CARBURETOR
INLETPLATE
FUELINLET
THROTTLE FLY
FIGURE9.EXPLODEDVIEWOFCARBURETOR
19