User manual

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11. Adjustment Possibilities for the Model Car
a) Engine Fine Tuning
Aftertherun-instageoftheengine(seechapter8.h),youmaystartthenetuningprocesstoincreasetheperfor-
mance. To that effect, optimise the mixture for idle speed (and transfer to full throttle) at the idle speed mix adjustment
screw and at the main jet needle for full throttle.
Thisnetuningissignicantlysimpliedbythecarburettorwiththematerialcombinationaluminium/plasticusedin
this vehicle. Conventional full metal carburettors become very hot in operation. This evaporates parts of the fuel in the
carburettor already. The lower heat intake of the plastic prevents this effect in the carburettor installed here.
Adjusting the main jet needle (full throttle mix)
• Starttheengineandremovetheglow-plugstarterasusual.
• Lettheenginewarmupforapproximately1min.
• Drivethemodelasusual.
• Iftheengineruns'toorich',tunedownthemixbytwistingthemainnozzleneedleinwardsby1/16thofaturnuntil
you have achieved the desired setting.
• Ensurethatthemixtureisnottoolean,sincethemotor'slubricationisnolongerensuredthen.Aslightwhitesmoke
vane should be visible from the exhaust at all times.
Performance increase by higher nitromethane share
Asalreadydescribedinchapter8.i),thenitromethaneshareshouldusuallynotexceed25%inracingoperation.
Foranevenbetterperformance,youcanchangetoafuelwithupto30%nitromethane.However,thereisthedan-
ger that the engine would show no satisfactory road performance anymore if you return to a fuel with a lower nitro
methane content.
If you want to permanently drive with a fuel with a high nitro methane content, we also recommend replacing the
present cylinder head gasket with a thicker one to reduce compression.
If you do not reduce compression, the engine may overheat and run incorrectly!
Adjusting the idle mix adjusting screw
• Starttheengineandrstadjustthemainjetneedleasdescribedabove.
• Reducethespeeduntilthecentrifugalclutchdoesnotengageanymoreandthewheelsstopturningwhenyoutake
the model off the ground.
• Leavetheenginerunningatidlespeedforapproximately10-15seconds.
• Whileyouareholdingthemodelwithyourhand,driveatfullthrottleoncebrieyandstrongly.Takecarenotto
contact moved or hot parts!
• Iftheenginestallsassoonasyourunatfullthrottle,theidlespeedmixistoolean.
• Enrichthemixbyunscrewingthescrewby1/16rotationscounter-clockwisewhiletheengineisswitchedoff.
• Restarttheengineandrepeattheprocedureuntilthespeedtransitionfromidlespeedtofullthrottleissoftand
spontaneous. A short delay in reaction is normal.