Troy-Bilt 4 Cycle Trimmer Repair Manual

							  
ROCKERARMCLEARANCE 
Thisrequiresdisassemblyoftheengine.Ifyoufeel 
unsureorunqualifiedtoperformthis,taketheunittoan 
authorizedservicecenter. 
NOTE:Inspectthevalvetorockerarmclearancewitha 
feelergaugeafterthefirst10hoursofoperation 
andthenevery25hoursofoperationthereafter. 
•Theenginemustbecoldwhencheckingoradjusting 
thevalveclearance. 
•Thistaskshouldbeperformedinside,inaclean,dust 
freearea. 
1. 
Removethemufflercoverbypressingdownonthe 
cornerwithaflatbladescrewdriver(Fig.36).Slide 
thenotchesonthesidesofthemufflercoverover 
thetabsontheenginecoverandremove 3.Removethescrewbehindtheenginecover(Fig.38). 
Screw 
Fig.38 
4.Disconnectthesparkplugwire. 
5.Cleandirtfromaroundthesparkplug.Removethe 
sparkplugfromthecylinderheadbyturninga5/8in. 
socketcounterclockwise. 
6.Removetheenginecover(Fig.37). 
7.Cleandirtfromaroundtherockerarmcover. 
Removethescrewholdingtherockerarmcoverwith 
alargeflatbladescrewdriverorTorxT25bit 
(Fig.39).Removetherockerarmcoverandgasket. 
Fig,36 
2.Removethetwo(2)screwsontopoftheenginecover 
withaFlat-headorT-20Torxscrewdriver(Fig.37). 
TopViewOfTheEngine 
EngineCover, 
Screws RockerArmCover 
SparkPlugHole 
Fig.37 Fig.39 
8.Pullthestarterropeslowlytobringthepistontothe 
topofitstravel,(knownastopdeadcenter).Check 
that: 
Thepistonisatthetopofitstravelwhilelookingin 
thesparkplughole(Fig.39). 
Bothrockerarmsmovefreely,andbothvalvesare 
closed. 
Ifnot,repeatthisstep. 
21  
						

							  
. 
Slidethefeelergaugebetweentherockerarmand 
thevalvereturnspring.Measuretheclearance 
betweenthevalvestemandrockerarm(Fig.40). 
Dobothintakeandexhaustvalves. 
RockerArms 
Nuts 
/ 
/ 
FeelerGauge 
Gasket 
Fig.40 
Therecommendedclearanceforbothintakeand 
exhaustis.003-.008in.(.078-0.152mm).Usea 
standardautomotive.005in.(0.127mm)feelergauge. 
Thefeelergaugeshouldslidebetweentherockerarm 
andvalvestemwithaslightamountofresistance, 
withoutbinding(Fig.41). 10.Iftheclearanceisnotwithinspecification: 
a.Turntheadjustingnutusinga5/18inch(8mm) 
wrenchornutdriver(Fig.41). 
•Toincreaseclearance,turntheadjustingnut 
counterclockwise. 
•Todecreaseclearance,turntheadjustingnut 
clockwise. 
b.Recheckbothclearances,andadjustasnecessary. 
11.Reinstalltherockerarmcoverusinganewgasket. 
Torquethescrewto20-30in.lb(2.2-3.4N.m). 
NOTE:Arockerarmcovergasket,Part#791-182099 
canbepurchasedfromyourlocalauthorized 
dealer. 
12.Reinstalltheenginecover.Checkalignmentofthe 
coverbeforetighteningthescrews.Tightenscrews. 
13.Replacethemufflercover.Slipthelongtabsonthe 
mufflercoverintotheenginecover.Slidethe 
notchesonthesideofthemufflercoveroverthe 
tabsontheenginecoverandsnapintoplace 
(Fig.36). 
14.Checkthesparkplugandreinstall.SeeReplacing 
theSparkPlug. 
15.Replacethesparkplugwire. 
AdjustingNut 
RockerArm 
.003-.006in. 
(.076-0.152mm) 
ValveStem 
Fig.41 
22  
						

							  
REPLACINGTHESPARKPLUG 
UseonlyChampionRDZ19Hsparkplugorequivalent. 
Thecorrectairgapis0.025in.(0.655mm.).Removethe 
plugafterevery25hoursofoperationandcheckits 
condition. 
1.Stoptheengineandallowittocool.Grasptheplug 
wirefirmlyandpullthecapfromthesparkplug. 
2.Cleandirtfromaroundthesparkplug.Removethe 
sparkplugfromthecylinderheadbyturninga5/8in. 
socketcounterclockwise. 
3.Replacecracked,fouledordirtysparkplug.Setthe 
airgapat0.025in.(0.655mm.)usingafeelergauge 
(Fig.42). SPARKARRESTORMAINTENANCE 
1.Removethemufflercover.SeeRockerArm 
Clearance,Pg.22. 
2.WithaflatbladescrewdriverorTorxT-20bit, 
removethescrewattachingthesparkarrestorcover 
tothemuffler(Fig.43). 
MufflerSparkArrestorScreen 
iiiiiiiiiiiiiiiii_ki_iiiiiiiiiiiiiiiiiiiiiiiii 
Fig.42 
I_lbCAUTION:Donotsandblast,scrape,orclean  electrodes.Gritintheenginecoulddamagethe 
cylinder. 
4.Installacorrectlygapedsparkpluginthecylinder 
head.Tightenbyturningthe5/8in.socketclockwise 
untilsnug. 
Ifusingatorquewrenchtorqueto; 
110-120in.-Ib.(12.3-13.5Nom). 
Donotovertighten. 
NOTE:AreplacementsparkplugPart#791-180852B 
canbepurchasedfromyourlocalauthorized 
dealer. Tab_Screw 
/SparkArrestorCover 
Slot 
Fig.43 
3.Pullthetabonthesparkarrestorcoveroutofthe 
muffler.Removethesparkarrestorcover. 
4.Removethesparkarrestorscreenfromthespark 
arrestorcover. 
5.Cleanthesparkarrestorscreenwithawirebrush,or 
replace. 
6.Reinstallthesparkarrestorscreen,sparkarrestor 
cover,andscrew. 
NOTE:AreplacementsparkarrestorscreenPart# 
791-180890canbepurchasedfromyourlocal 
authorizeddealer. 
ACCESSORIES/REPLACEMENTPARTS 
4-CycleOil.........................753-1249 
OilFillPlug/Dipstick................791-182378 
SparkPlug.........................791-180852B 
SparkArrestorScreen................791-180890 
ReplacementLineCartridge...........753-1156 
InnerReelSpring....................791-610317B 
BumpKnobTM......................791-153066B 
FuelCap..........................791-181083 
ShoulderHarness...................791-682075B 
Thesereplacementpartscanbepurchasedfromyour 
localauthorizeddealerorbycalling1-330-558-7220or 
1-866-840-6483. 
23  
						

							  
CLEANING 
,_WARNING:Toavoidseriouspersonalinjury,  alwaysturnyourtrimmeroffandallowitto 
coolbeforeyoucleanordoanymaintenance 
onit. 
Useasmallbrushtocleanofftheoutsideoftheunit.Do 
notusestrongdetergents.Householdcleanersthat 
containaromaticoilssuchaspineandlemon,andsuch 
askerosene,candamageplastichousingorhandle. 
Wipeoffanymoisturewithasoftcloth. 
STORAGE 
Neverstoretheunitwithgasolineinthetankwhere 
fumesmayreachanopenflameorspark. 
Allowtheenginetocoolbeforestoring. 
Storetheunitlockeduptopreventunauthorizeduse 
ordamage. 
Storetheunitinadry,wellventilatedarea. 
Storetheunitoutofthereachofchildren. 
Storetheunitinoneofthree(3)positions: 
1.Theunithangingbythecuttingattachmentend. 
2.Theunithangingbytheengine. 
3.Theunitsettinguprightonthecuttingattachment 
shieldandenginefeet. LONGTERMSTORAGE 
Iftheunitwillbestoredforanextendedtime, 
1.Drainallgasolinefromthegastankintoacontainer. 
Donotusegasthathasbeenstoredformorethan 
60days.Disposeoftheoldgasolineinaccordance 
toFederal,State,andLocalregulations. 
2.Starttheengineandallowittorununtilitstalls.This 
ensuresthatallgasolinehasbeendrainedfromthe 
carburetor. 
. 
Allowtheenginetocool.Removethesparkplugand 
put1oz.(30ml)ofhighqualitymotoroilintothe 
cylinder.Pullthestarterropeslowlytodistributethe 
oil.Reinstallthesparkplug. 
NOTE:Removethesparkpluganddrainalloftheoil 
fromthecylinderbeforeattemptingtostartthe 
trimmerafterstorage. 
4.Changetheoil.SeeChangingtheOil,Pg.17. 
DisposeoftheoldoilinaccordancetoFederal, 
State,andLocalregulations. 
5.Thoroughlycleantheunitandinspectforanyloose 
ordamagedparts.Repairorreplacedamagedparts 
andtightenloosescrews,nutsorbolts.Theunitis 
readyforstorage. 
TRANSPORTING 
Allowtheenginetocoolbeforetransporting. 
Securetheunitwhiletransporting. 
Drainthegastankbeforetransporting. 
Tightengascapbeforetransporting. 
24  
						

							  
CAUSE 
IgnitionswitchisOFF 
Emptyfueltank 
Primerbulbwasntpressedenough 
Engineflooded 
OldGasoline 
Fouledsparkplug 
CAUSE 
AirFilterisPlugged 
OldGasoline 
Impropercarburetoradjustment 
CAUSE 
OldGasoline 
Impropercarburetoradjustment 
Cuttingheadboundwithgrass 
Dirtyairfilter 
CloggedSparkArrestorScreen 
CAUSE 
OldGasoline 
Impropercarburetoradjustment 
CloggedSparkArrestorScreen 
CAUSE 
Cuttingheadboundwithgrass 
Cuttingheadoutofline 
Innerreelboundup 
Cuttingheaddirty 
Linewelded 
Linetwistedwhenrefilled 
Notenoughlineisexposed ACTION 
TurnswitchtoON 
Fillfueltank 
Pressprimerbulbfullyandslowly5-7times 
Usestartingprocedurewithchokeleverinthe 
RUNposition,Pg.11 
Drainfueltank/AddfreshGasoline 
Replaceorcleanthesparkplug 
ACTION 
Replaceorcleantheairfilter 
Drainfueltank/AddfreshGasoline 
AdjustperinstructionPg.20 
ACTION 
Draingastank/AddfreshGasoline 
Taketoanauthorizedservicedealerfor 
carburetoradjustment 
Stoptheengineandcleanthecuttingattachment 
Cleanorreplacetheairfilter 
CleanorReplace.SeePg.23 
ACTION 
Drainfueltank/AddfreshGasoline 
Taketoanauthorizedservicedealerfor 
carburetoradjustment 
CleanorReplace.SeePg.23 
ACTION 
Stoptheengineandcleancuttingattachment 
Refillwithnewline 
Replacetheinnerreel 
Cleaninnerreelandouterspool 
Disassemble,removetheweldedsection 
andrewindtheline 
Disassembleandrewindtheline 
PushtheBumpKnobandpulloutlineuntil 
4inches(102mm)oflineisoutsideofthe 
cuttingattachment 
CAUSEACTION 
OilincuttingheadCleanthecuttingattachment 
Iffurtherassistanceisrequired,contactyourauthorizedservicedealer. 
25  
						

							  
ENGINE 
EngineType.................................................................Air-Cooled,4-Cycle 
Displacement.................................................................1.6cu.in.(26.2cc) 
ClutchType.........................................................................Centrifugal 
OperatingRPM.................................................................7,200-8,300rpm 
IdleSpeedRPM.................................................................3,000-4,500rpm 
IgnitionType.........................................................................Electronic 
IgnitionSwitch....................................................................RockerSwitch 
Valveclearance(intakeandexhaust)......................................003-.006in.(.076-.0152mm) 
SparkPlugGap............................................................0.025inch(0.655mm) 
Lubrication..........................................................................SAE30Oil 
CrankcaseOilCapacity............................................................3.4oz(100ml) 
Fuel................................................................................Unleaded 
Carburetor................................................................Diaphragm,All-Position 
Starter............................................................................AutoRewind 
Muffler.......................................................................BaffledwithGuard 
Throttle....................................................................ManualSpringReturn 
FuelTankCapacity.................................................................20oz(591ml) 
FuelTank.......................................................................HDPolyethylene 
DriveShaftHousing......................................................AluminumTube(EZ-LinkTM) 
ThrottleControl.................................................................Finger-TipTrigger 
UnitWeight(NoFuel,withJ-handle,CuttingattachmentshieldandCuttingattachment).......13.5Ibs(6.13kg) 
CuttingMechanism........................................................DualStringCuttingHead 
LineSpool...................................................................BumpLineReleaser 
LineSpoolDiameter...........................................................3inches(76.2mm) 
TrimmingLineDiameter.....................................................0.095inches(2.41mm) 
CuttingPathDiameter..........................................................17inches(38.1cm) 
26  
						

							  
PartNumbersOnFollowingPage 
@ 
@ 
@ @ ENGINEPARTS-MODELTB475SS 
4-CYCLEGASTRIMMER 
(ppn-41ADT47C063)(SerialNumber011......andgreater) 
® 
® 
@ 
@ 
Reissued12/0127  
						

							  
ENGINEPARTS-MODELTB475SS 
4-CYCLEGASTRIMMER 
(ppn-41ADT47C063)(SerialNumber011.........andgreater) 
ItemPartNO..DescriptionItemPartNO.Description 
179%182338EngineCover47791-181247Palnut 
279%182339EngineCoverScrews48753-1199RecoilPulley 
379%181025ValveCoverScrew49791-613102RecoilSpring 
479%182098ValveCover50791-182366NutClip 
579%182099ValveCoverGasket51791-181079PullHandle 
6791-182340RockerAdjustmentNut52791-611061RopeGuide 
779%182101RockerArmPivot53791-613103Rope 
879%182100RockerArm54791_181020StarterHousingScrew 
9791-182341RockerArmStud55753_1237StarterHousingAssembly 
1079%182103ValveSpringRetainer(includes49-56) 
1179%181038ValveSpring56791-182368ClutchWasher 
1279%182102PushRodGuide57753-1238ClutchwithSpacer 
1379%181033PushRod58791-153592ClutchDrum 
1479%182700CylinderHead(includes9&12)59753-1239ClutchCover 
1579%182344CylinderScrew60791_145569AntFRotationScrew 
1679%182345IntakeBaffle61753-1240Screw 
1779%182749CarburetorMountGasket62753-1241Nut 
1879%181034Nut63791-181345ClutchCoverScrew 
1979%182347CarburetorMount(includes18)64791-182725IgnitionModulewithScrews 
2079%182348CarburetorMountScrew65791-181065Spacer 
2179%182732CarburetorGasket66791-181867Flywheel 
22A791-182654CarburetorwithPrimer67791_182743ShroudAssemblywithScrews 
22B753-1225CarburetorwithPrimer68753-1244CrankcaseAssembly 
23791-181751O-Ring,Carburetor(includes69_73) 
24753-1227AirFilter/ChokeCoverAssembly69791-610309OilSeal 
(includes27&28)70791-182372Bearing 
2579%182097BreatherTube71791-182380Crankshaft 
2679%181750AirFilterMountingScrew72791-182375900Elbow 
27791-181757AirFilter73791-182379BreatherHose 
28753-1228AirFilterCover74791-181015CamGear 
29753q229FuelCap75753-1242CamFollowerSet 
3079%182352FuelReturnLine76791-181013CamBracket 
3179%182353FuelPick-UpLinewithFilter77791-181012CamBracketScrew 
3279%181080Screw78791-181040Valves,IntakeandExhaust 
33791-182354Washer79791-182374CylinderGasket 
34753q230FuelTankAssembly(includes29_31)80791-181018OilPanGasket 
35791_182356FuelTankShield81791-182377OilPan(includes80&82) 
36A791-182357ThrottleCable82791-181020OilPanScrew 
36B753-1231ThrottleCable83791-182378DipstickAssembly(includes84) 
3779%182358MufflerBaffle84791-182290O-Ring 
3879%181048MufflerGasket85791-181009ConnectingRod 
3979%182359Muffler(includes40,42*44)86791-181008WristPinButton 
40791-180890SparkArrestorScreen87753-1243Piston 
4179%181045ScreenCover88791-181008WristPin 
4279%181046Screw89791-182295PistonRingSet 
4379%182360MufflerShield90791-182409Washer 
4479%182361MufflerMountingScrew91791-181861Screw 
4579%182362MufflerCover92791-612468CompressionSpring 
4679%182804SwitchWireAssembly93791-182537Grommet 
791_180852BSparkPlug 
753_1245ShortBlockAssembly 
(includes3-7,68-89) 
791_182745CylinderAssembly 
(includes9,12,14&79) 
791-180142StarterPawlRepairKit 
791_182156CarburetorRepairKit 
753_1248GasketDiaphragmRepairKit 
Partsnotshown 
28Reissued12/01  
						

							  
BOOMANDTRIMMERPARTS-MODELTB475SS 
4-CYCLEGASTRIMMER 
(ppn-41ADT47C063)(SerialNumber011.........andgreater) 
ItemPartNo. 
1753-1211 
2791-OO042 
3791-182690 
4791-182673 
5791-180869 
6791-181070 
7791-182167 
8791-182168 
9753-1247 
10753-1190 
11791-182057 
12791-181617 
13791-181981 
14791-181886 
15791-182388 
16791-181166 
17791-153597 
18791-145669 
19791-180647 
20791-180548 
21791-180553 
22791-18064£ 
23791-153619 
24791-610660 
25791-610317B 
26753-1155 
27791-153066B 
28791-610327 
OptionalAccessories 
791-180120 
753-1156 
791-682075 
753-1249 
791-180870 
ternsNotShown ® 
®/ 
®® 
@.@ 
@ 
ThrottleHousingandTrigger 
Assemb.ncludes2&3,/K_ 
Throttle]rigger 
ThrottleTriggerSpring 
SwitchAssembly 
DeluxeD-HandleAssembl_includes6-6, 
Scre_ 
DeluxeD-Handle(_) 
BottomClamo 
UpperDriveShaftHOUSingAssembly(_t_/-_ 
EZ-LinkTMCoupler(includes11-14)\_-/_1I\ 
Screw--___\_--- 
AdjustmentKnob 
KnobRetainingNut/__-_.__t-_\ 
LowerDriveShaftHousingAssembly//____\\ 
LowerClampAssembly(includes18t 
Anti-RotationScrew 
ShieldMountingHardware 
ShieldandBladeAssemblylincludes21 
BladeAssembly 
GearboxAssembly 
OuterSpool&EyeletAssembly 
RetainingRing 
Spring 
InnerReel 
BumbHeadKnobAssembly 
HarnessClip 
ReplacementLine0.095Diameter 
ReelandLineAssembly 
ShoulderStrapAssembl) 
4-CycleOil 
HandleMountingHardware 
ncludes4screws&4nuts_ 
Reissued12/0129  
						

							  
30