Team Losi LST XXL User manual

Operations Guide
Not responsible for errors. All prices subject to change without notice. Losi, a Division of Horizon Hobby, Inc.

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Introduction
Thank you for choosing the Losi LST XXL™ Monster Vehicle. This is a highly developed o-road model that features
a sophisticated computer-based radio system and does require some mechanical experience and direct adult
supervision. This guide contains the basic instructions and drawings for operating and maintaining your new LST
XXL. Please take the time to read through it completely before running the model. Your hobby dealer cannot
under any circumstances, accept a model for return or exchange that has been run.
Customer Support Contact:
Horizon Hobby, Inc.
4105 Fieldstone Road
Champaign, IL 61822
1-877-504-0233
[e-mail]
Safety Precautions
THIS IS NOT A TOY! The LST XXL is a sophisticated, high-performance radio controlled model, which needs to be
operated with caution and common sense. Failure to operate this model in a safe and responsible manner could
result in personal and/or property damage. It is your responsibility to see that the instructions are followed and
precautions adhered to.
The LST XXL is not intended for use by children without direct adult supervision. Losi and Horizon Hobby shall
not be liable for any loss or damages, whether direct, indirect, special, incidental or consequential arising from the
use, misuse or abuse of this product or any product required to operate it.
* This is still a model; don’t expect it to do unrealistic stunts.
Warnings
The LST XXL is equipped with a reverse gear. Just like a real automobile you must wait for the model to
come to a complete stop before shifting between forward and reverse. Failure to do so will cause damage to
the transmission.
• Fuelisdangerousifhandledcarelessly.Followalldirectionsandprecautionsonthefuelcontainer.
• Keepfuelandallchemicalsoutofthereachofchildren.
• Alwayskeepthefuelcontainerclosedandneverusearoundanopenameorwhilesmoking.
• Theexhaustemitspoisonouscarbonmonoxidefumes.Alwaysrunthemodelinawellventilatedareaand
never attempt to run it indoors.
• Thetopoftheengineandtheexhaustpipeareextremelyhotduringandforatimeafteruse.Usecautionnot
to touch these parts, especially when refueling.
• Theenginecanbeloud,especiallywhenruninaconnedarea.Ifyoundthenoiseobjectionable,useear
protection.
• Thismodeliscontrolledbyaradiosignalthatissubjecttointerferencefromsourcesoutsideyourcontrol.
Interference can cause temporary loss of control so it is advisable to always keep a safety margin in all
directions to avoid collisions.
• Alwaysoperateyourmodelinanopenareaawayfrompeopleandcars.Thepotentialspeedofthismodelcan
causeinjuryordamage.
Required Equipment
You will need the following items to operate your new LST XXL.
• Losi®Nitrotane™20%SportFuel.(LOSF0020orLOSF0120)Thisistheonlyfuelthatsupportstheengine
warranty.
• Fuelbottle(LOSB5201)
• 1Csizealkalinebatteryfortheigniter(igniternotincluded)
• 7.2VbatteryandchargerfortheSpin-Start(included)
• Optional:RechargeableGlowIgniter(LOSB5221)
• Optional:Chargerforreceiverbattery

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Tools You Will Find Handy
InadditiontothetoolsincludedwiththeLSTXXL,youwillndthefollowingbothusefulandinsomecases
necessary.
• SmallatbladeandPhillipsscrewdrivers
• Needle-nosepliers
• Quality.050-inch,1/16-inch,5/64-inch,3/32-inch,1.5mmand2.5mmhex(Allen)drivers
Engine Break-In and Adjustments
Breakinginyournewengineiscriticalforproperperformance.Failuretofollowthebreak-inprocedurescancause
damageandshortenedenginelife.Duringbreak-inandwhenrunning,alwaysuseLosiNitrotane20%SportFuel.
Althoughthecarburetorispreadjustedatthefactory,youmustbefamiliarwiththefollowingadjustmentsand
break-inprocedure.Ifyouchangefuelorrunindramaticallydierentenvironments(hot/cold,high/lowelevation,
etc.)youwillprobablyhavetoadjustatleastthehigh-speedneedletopreventoverheatingandmaintainproper
performance. Never, under any circumstances allow the engine to rev freely with the wheels o the ground.
Break-In Procedure
1. Therstthreetanksoffuelshouldberunwiththehighandlowspeedneedlesnoticeably“rich”(see
explanationbelow).Thereshouldbeaslightsluggishnessandthicksmokewhenacceleratingwiththe
smoke decreasing as the model gains speed. At speed, there should still be a noticeable trail of smoke from
theexhaustpipe.RuntheLSTXXLonaatsurfaceinanovalpattern.Easeintothethrottleasyouaccelerate
on the straight sections, easing o as you approach turns—letting the model roll through the turn before
easing back on the throttle. This will also allow you to get a feel for the steering response and handling
characteristics of the model.
2. Youcanalsobreakintheenginebyplacingthemodelagainstawallorxedobjectandallowingtheengine
toidlethroughtwofulltanksoffuel.Youmayhavetoleanthelow-speedmixture(slightly)asnotedbelow.
3. Note:The2-speedwillnotshiftduringbreak-in.Donotexpectthe2-speedtoshiftuntilatleastthefthor
sixthtankoffuel.Ifyouwantittoshiftearlierfollowthedirectionsin“2-SpeedAdjustment”.
Understanding “Rich” and “Lean” Fuel Mixture
AdjustingthecarburetorisoneofthemostcriticalfacetsofrunninganitropoweredRCvehicle.Thefuelmixture
isreferredtoasbeing“rich”whenthereistoomuchfueland“lean”whenthereisnotenoughfuelfortheamount
ofairenteringtheengine.Theamountoffuelenteringtheengineisadjustedwithhigh-andlow-speedthreaded
needle valves. The low-speed needle is located in the front of the moving slide. The high-speed needle sticks
straightupatthebackofthecarburetor.Bothfeatureaslottedheadthatisusedasareferenceandreceptacle
foraatbladescrewdriverforadjustments.Themixtureismadericherbyturningtheneedlecounterclockwise
andleanerbyturningclockwise.Anoverly“rich”mixturewillyieldsluggishaccelerationandperformancewith
thicksmokefromtheexhaust.A“lean”mixturecancausetheenginetohesitatebeforeacceleratingor,insome
cases, to lose power momentarily after the initial acceleration. A lean mixture also makes the engine run hotter
than desired and does not provide enough lubrication for the internal engine components, causing premature
wear and damage. It is always advisable to run the engine slightly rich and never lean to avoid overheating and
possible damage.

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Base Start-up Settings from the Factory
High-SpeedNeedle—23/4turns out from bottom
Low-SpeedNeedle—21/2turns out from bottom
Engine Tuning
After the engine is broken in, you can tune it for optimum performance. When
tuning, it is critical that you be cautious of overheating as severe damage and
prematurewearcanoccur.Youwanttomakeallcarburetoradjustmentsin
“onehour”increments.
Low-Speed Adjustment
Thelowspeedadjustmentaectstheidleandslightly-o-idleperformance.
Theoptimumsettingallowsthemotortoidleforatleast8−10seconds.The
model should then accelerate with a slight amount of sluggishness and a
noticeable amount of smoke. The simplest way to check this is to make sure
theenginehasbeenwarmedupandlettheengineidlefor8−10seconds.If
the low-speed mixture is so far o that the engine won’t stay running that
long, turn the idle stop screw clockwise, increasing the idle speed. With
the engine at idle, pinch and hold the fuel line near the carburetor, cutting
otheowoffuel,andlistencloselytotheenginerpm(speed).Ifthelow-
speed needle is set correctly, the engine speed will increase only slightly and then die. If the engine increases
several hundred rpm before stopping, the low-speed needle is too rich. Lean the mixture by turning the needle
clockwise one hour and trying again. If the engine speed does not increase but simply dies, the needle is too
lean and needs to be richened up by turning the needle counterclockwise one hour before trying again. After
youhaveoptimizedthelow-speedsetting,theenginewillprobablybeidlingfaster.Youwillhavetoadjustthe
idle stop screw counterclockwise to slow the engine idle speed down. The engine should accelerate at a constant
pace without hesitating.
Hi-Speed Adjustment
After initial acceleration, the engine should pull at a steady rate while maintaining a two-stroke whine and a
noticeable trail of smoke. If the engine labors and is sluggish with heavy smoke, the mixture is too rich and needs
to be leaned by turning the high-speed needle clockwise in one-hour increments until it runs smoothly. If the
engine isn’t smoking or starts to die after acceleration, it is too lean and you must richen the mixture by turning
the needle counterclockwise. Don’t be confused by the sound of the engine and the actual performance. A
leaner mixture will produce an exhaust note with a higher pitch but this does not necessarily mean improved
performance, as the engine is on the verge of overheating and may incur possible damage. Ideally you want to
run the engine so that it is on the slightly rich side of optimum. This will give you the best combination of speed
and engine life. CAUTION:Theengineistooleanandoverheatingifitacceleratesrapidlywithahigh-pitched
scream then seems to labor, stops smoking, or loses speed. This can be caused by the terrain, atmospheric
conditions, or drastic altitude changes. To avoid permanent engine damage, immediately richen the mixture by
turningthehigh-speedneedlecounterclockwiseatleast“twohours”andbepreparedforfurtheradjustments
before running any more. Note:Thenormaloperatingtemperatureasseenonyourradioscreenshouldbeinthe
190to220°F(88to105°C)range.
1 Hour
2 Hour
Carb Adjustments:
Makeallcarburetoradjustments
in one-hour increments.
Imagine the slot in the needle is
thehourhandonaclock.Adjust
it as though you were moving
the hour hand from one hour to
the next or previous one.
High-Speed Needle
As you turn this clockwise (leaner),
less fuel enters the engine.
Turning it counterclockwise
(richer) allows more fuel to enter
the engine.
Idle Speed Screw
As you turn this clockwise, it
increases the carburetor opening
at idle and increases idle speed.
Turning it counterclockwise
decreases the opening and idle
speed.
Low-Speed Needle
As you turn this clockwise (leaner),
less fuel enters the engine.
Turning it counterclockwise
(richer) allows more fuel to enter
the engine.
Richer Leaner
Idle Speed
Screw
Faster
Slower
High-Speed
Needle
Carb Opening
Leaner
Richer
Low-Speed
Needle

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About Glow Plugs
The glow plug is like the ignition system in your automobile. The coiled element in the center of the plug glows
redhotwhenconnectedtoa1.5-voltbattery(locatedintheigniter).Thisiswhatignitesthe
fuel/airmixturewhencompressedinthecylinder.Aftertheengineres,theheatgenerated
bytheburningfuelkeepstheelementhot.Commonreasonsfortheenginenotstartingare
the1.5-voltbatterybeingweak,theglowplugbeingwetwithfuel,ortheelementburnedout.
Useaspareglowplugtochecktheigniter.Iftheignitermakestheelementglow,removethe
plug from the engine to check it in the same manner. A wet glow plug means there is excess
fuel in the engine. To eliminate this, put a rag over the head and turn the engine over a few
secondswithyourSpin-Start.Reinstalltheglowplug,makingsureyouhavethebrassgasket
on it. The engine should now start.
Testing the Temperature
AlthoughtheDX3SRadiooerstemperaturereadout,thefollowingisahandybackupmethod.Theideal
operatingtemperaturefortheenginewillvarywiththeairtemperaturebutingeneralitshouldbeinthe190to
220°F(88to105°C))range.Asimplewaytochecktheenginetemperatureistoputafewdropsofwateronthe
topofthehead/heatsink.Itshouldtake3−5secondsforthewatertoevaporate.Ifitboilsawayquicklytheengine
isoverheatingandthehigh-speedneedleneedstoberichened(turnedcounterclockwise)atleast“twohours.”
About the Radio
TheSpektrumDX3SradioinstalledintheLSTXXLisaprofessionallevelsystemwithmorethantheusualfeatures
youmaynduseful.Besuretoreadthroughtheincludedradiomanualforcompleteinstructions.Thefollowingis
a simple guide refering to items that are commonly used and/or needed to run your model.
1. Power Switch - Turns your transmitter ON and OFF
2. Steering Wheel - Controls the steering of your model
3. Steering Trim Tab - Allows you to ne-tune the neutral position
of the steering
4. Throttle Trigger - Pull back for throttle and push forward for
brakes
5. Throttle Trim Tab - Allows you to set the idle/brake of the
model
6. Transmitter Display - Digital readout shows battery voltage,
temperature, RPM/Speed and functions/settings
7. Transmitter Antenna - Transmits signal to the receiver in the
model
8. AUX - Lever for forward/reverse
Radio Operation
It is important that you familiarize yourself with the radio system, as
this is your direct link to the model.
• Neverrunyourmodelwithlowreceiverortransmitterbatteries.
• Alwaysfoldtheantennatotheuprightpositionbeforerunning
your model.
• Neverleavethepoweronorthebatterieswillnotlastlong.
• AlwaysturnthetransmitterONbeforeturningthemodelON.
• Whennishedrunning,alwaysturnthemodelOFFbeforethetransmitter.
• Forbestoperation,itwillbenecessarytokeepthe“trims”adjustedforboththesteeringandthrottleasnoted
on the following pages.
1
2
3
5
48
6
7
DYN2495 Shown

Page 6
Steering Trim:Themodelshouldgostraightwithoutturningthesteering
wheel.Ifnot,tapthetrimleverfoundjustaboveandtotherightofthe
steeringwheelinthedirectionneededforthemodeltogostraight.Each
tap of the trim button will be accompanied by an audible tone indicating
a change has been made. It may take several taps to get the correct trim
setting.
Throttle Trim:Themodelshouldidlewithoutthetiresrotatingwhenthe
triggerisatitsneutralposition.Ifnot,tapthetrimleverfoundjustabove
and to the left of the steering wheel to reposition the throttle servo and
close the carburetor and apply more brakes. Note that additional braking
force is applied when you push the trigger forward.
Synchronizing the Steering Servos:Ifyouremovethesteeringservosor
theservosaversyouwillprobablyhavetomakesomesmalladjustmentstoensuretheyareworkingtogetherat
maxium capacity. With the servo savers removed and the linkaged attached,
• Turnontheradioandresetthesteeringtrimtoread“0”(whichisneutral)ontheradioscreen.
• Loosenthesetscrewssecuringthelinkageslightlyandmounttheservosaverssotheyaretimedascloseas
possible like that seen in the photo.
• Usethesteeringtrimonthetransmittertone-tunethetimingoftheservosavers.
• Makesurethefronttiresarepointingforwardandlockthesteeringlinkageinplacebytightening
the setscrews.
Telemetry Sensors
• Thebatterypowerofthereceiverpackwillautomaticallyregisteronthe
readout screen.
• Theenginetemperaturerequiresthatthetemperaturesensor(SPM1450)be
installedaroundtheheadjustabovetheheadboltsasseeninthephoto.Note:
The temperature sensor must be removed before removing the head from the
engine. There is an external plug near the radio box which will allow you to
disconnect it if you wish to remove the engine for cleaning.
• TheRPM/Speedsensor(SPM1452)mountsdirectly
below the front of the radio box. It must be kept clean
to operate correctly. There is a silver stripe on the drive
coupler(justbelowthesensor)thatmustalsobekept
clean.Useonlyasoftbrushtocleanthese–DoNot
UseAnySolventsatanytimeontheseitems.Ifthe
silverstripegetsremoveduseonefromthe(SPM1512)
TelemetryRPMstickersheet.
Maintenance
In addition to the service needs pointed out in this guide,
you should try to maintain your new LST XXL for proper performance and to prevent wear. If dirt gets in the
movingpartsitcanseriouslyhindertheperformanceofthemodel.Usecompressedair,asoftpaintbrushand/
or toothbrush to remove dirt and dust. Avoid using solvents, if possible, as this can acutally wash the dirt into
bearings and areas not accessible without disassembly, causing additional wear. We suggest you follow these
basic guidelines.
• Removeasmuchfreestandingdirtanddustasnotedabove.
• Neverleavefuelinthetankformorethanacoupleofhours.
• Whendonerunningforthedayorlonger,lettheenginerunoutoffuel.Removetheaircleanerandpoura
littleWD40orqualityafter-runengineoilintothecarburetorandspintheengineoverafewseconds.
• Ifneeded,cleanandre-oiltheaircleanerbeforeinstallingitbackonthemodel.
• Inspectthechassisforworn,broken,orbindingpartsandrepairasnecessary.

Page 7
Adjusting the Slipper
The slipper is a key component of the drivetrain that is designed to help
absorb sudden or large impacts that would otherwise stress various drivetrain
parts.YoushouldneverruntheLSTXXLwiththeslipperlocked(completely
tight).Theslippercanalsobeusedasatuningaidforextremelyslick
conditions.Toadjusttheslipper,startbyturningthe1/4-inchadjustment
nutclockwise(tighten)untilitgetstightandthespringiscompressed.Do
not overtightenasyouwillstripthenut.Nowturntheadjustmentnut
counterclockwise(loosen)onefullturn.Thisshouldbeagoodoverallsetting.
2-Speed Adjustment
Althoughpre-adjustedatthefactory,thetwo-speedcanbeadjustedtoshift
atthepointthatsuitsyoubest.Undernormalcircumstances,itshouldshift
slightly before the engine reaches maximum power. The actual distance traveled will vary with the gear ratio and
tuneoftheengine.Therearetwoadjustmentscrews(seeg1)thatmustbechangedevenlyforthetwo-speed
to function correctly. Turning these clockwise will make it shift later and require the engine to rev higher. Turning
themcounterclockwisewillmakeitshiftearlierandrequirelessenginespeed.Ifyoushouldgetlostadjustingthe
two-speed, start over at the factory setting by lightlybottomingouttheadjustmentscrewsandthenbacking
them out vefullturns.Theprocedureforadjustingthetwo-speedisasfollows.
• Removethegearcover.
• Turnthespurgearsuntiltheadjustmentholeisvisibleinthebellhousingbetweenthelargeandsmallspur
gears.
• Holdthesmallspurgearand,usingyourthumb,rotatetheslipperforwarduntilyoucanseetheheadofone
oftheadjustmentscrews.
• Usea5/64Allenwrenchtomakeyouradjustmentin1/2-turnincrements.Usethebentlegofthewrenchas
your guide.
• Turntheslipperforward1/2rotationtoadjusttheotheradjustmentscrewliketherst.
(Remember to always adjust BOTH screws the same amount)
• Testdrivethemodeltocheckthenewshiftpointandreplace the gear coverifsatised.
• Never run your model without the gear cover, as it is dangerous and gear damage will occur!
Turningtheadjustmentscrews
counterclockwisemakesthe2-speed
shift sooner; turning clockwise will
make it shift later.
x1
Slipper - 1 turn out
Fig 1
Always adjust BOTH adjustment screws evenly.
Later Sooner
Note:
Outer (1st) spur
gear removed for
photo

Page 8
Replacing the 2-Speed Gears
First (Low) Gear:
After removing the outer gear cover remove the large circlip at the
outerfaceofthegear.Removeandreplacethegearbeingsureto
insert the molded pins on the back of the gear with the holes in the
aluminumhub.Replacethecirclip.Note:Specialpliersaremadethat
make removal and installation of the circlip easier.
Replacing the Clutch Bell
Usea3/32”wrench(provided)toremovethe
retainingscrew(turncounterclockwise)while
rmlyholdingtheywheelwithapairofpliers.
Removethescrew,washersandclutchbell,
being careful not to lose any shims that may
beused.Removetheballbearingsandbrush
any loose dirt away from the bearing faces. Put
onlyONEdropofoilontheinsideface(theside
facingawayfromtheclutchshoes)nearthe
inner race of the bearing. Install the bearings
intothenewclutchbell.Beforereplacingthe
clutch bell, wipe out the inside with motor
spray,lacquerthinner,orasimilarcleaner(do
notusefueloroil-basedsolvents).Replace
the clutch bell and secure with the retaining
screw in the same manner used to remove it.
Note:donotover-tightenthescrew,asitisnot
necessary.
Second (High) Gear:
Removethenutandthethrustwasherassemblyfrom
the slipper. Slide both gears o of the shaft being
careful to leave the slipper pads in the steel slipper
cage.The2-speedclutchshoeswillbeinsidethe
bellforthehighgear.Usea1/16-inchhexwrenchto
remove the three button head screws and replace
thegear.Reinstallthehighgearwiththeclutchshoes
in the bell, the large washer, low gear assembly and
thrust washer assembly as seen in the exploded view.
Adjustperthe“AdjustingtheSlipper”instructionsand
replace the gear cover.

Page 9
Servicing the Dierentials
Thedierentialsshouldbeservicedperiodically.Besuretocleanandinspectallofthegearsandreplaceifseverely
worn.Alwaysuseplentyofhigh-qualitygrease(likeLosiLOSA3066)onallgears.NOTE:Thesecanalsobemadeinto
racing type viscous dis as noted below. Always service one di at a time and pay close attention to installing the
housingwiththe“TOP”markingupsoitcanbeseenlookingdownonthechassis.
Removing the Dierentials
• Removethetwoscrewsinthebottomattheextremeendofthechassis(g1)
• Removethefourscrewsinthebulkheadallowingthebumper/skidplatesandpinmountstobe
removed(g2).
• Removethediretainersandslidethediout(g3).NOTE:Onthefrontendonlyyouwillhavetoremovethe
lower front shock attachment screws and swing the shocks up and out of the way. On the rear end you will
needto“pop”otherearcamberlinks.
Dierential Service
• Removethethree5/64”capheadscrewsandthetopofthedierential
housing, then the di.
• Removethefour5/64”atheadscrewsfromtheringgearallowingit
to be removed.
• Inspecttheringandpiniongearsforwear;replaceifnecessary.
• Removethecrossshafts,bevelgears,andshimsforthecarrier.
• Cleanandinspectallparts;replaceasneeded.
• Checkallballbearings.Cleanorreplaceasnecessary.
• Removepinsfromoutdrives.Removeoutdrives,regreaseandreinstall.
• LubeallshaftsandgearswithLOSA3066assemblygreaseandreassemble.
• Loadcrossshaftswithgearsintothecarrierwithextragrease.Applytherubber
gasket to the carrier and reinstall ring gear.
• Luberingandpinionwithgreaseandreassemblediintodihousing.
• Reinstallintochassiswith“TOP”onhousingfacingup.
For Viscous Dierential
Insteadofgreaseyoucanusesiliconeuidinthedierential
foralimitedslipfeelasdesiredforracing.Simplyllthedi
up to the top of the gears before replacing the ring gear.
(Besuretoreinstallthegasket).Youmayhavetoreplace
the O-rings on the outdrives at the same time you change
to this type of dierential if the old ones are worn. Popular
siliconeuidforyourmodelisLosi10,000cs(LOSA5282)and
is available from your local hobby dealer.
Fig 1. Fig 2. Fig 3.
IMPORTANT:
Always reinstall
the thin gasket.

Page 10
Servicing the Transmission
The transmission should also be cleaned and serviced periodically. All gears and shafts should be closely
inspectedforwearandreplacedifnecessary.Alwaysuseahigh-qualitygreaseorlubricantlikeLOSA99203to
prevent premature wear and/or failure.
Removing the Transmission
1. Removethegearcover.
2. Removethethrottleandbrakelinkageaswellasthefwd/revlinkage.
3. Loosenthefourmotormountscrews(bottomofthechassis)andslidethe
motor back.
4. Remove2-speedspurgears.
5. Removethevetransmissionmountingscrewsandliftthetransmissionout.
6. Removetheoutdriveandten5/64”capheadscrews.Removethetransmission
case half.
7. Regreasethegearsandshafts,inspectingeachforwear.
8. Replaceanywornorfailedgears.
9. Wipeouttheinsideofthegearcase,removinganydebris,oldgreaseand
foreign matter.
10. Checkallballbearingsforfreemovementcleaningorreplacingasnecessary.
11. ReinstallgearsontheshaftslubingwithLOSA3066orLOSA99203LosiAssemblyGrease.
12. ReassemblethetransmissionlubricatingliberallywithLOSA3066orsimilarhigh-gradegrease.
13. Makesurethesetscrewsintheoutdrivecupsaretightened(alockingcompoundishighlysuggested).
14. Installthetransmissioninthechassis;resetthegearmeshbyusingasmallpieceofpaperbetweenthe
pinionandspurgears,applyingpressurewhileretighteningtheengine.Reconnectalllinkagesand
connetions as necessary.
2
FWD/REV Linkage
Throttle and Brake Linkage
14
3
5
1
6
*
*Note:
These 4 are
longer
2-56 x 3/4"