XTM Racing Mammoth ST, Руководство пользователя, Страница: 16 / 64

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SETTING THE HIGH SPEED NEEDLE VALVE:
❑
Start the engine and remove the glow starter from the glow plug, then allow the engine to warm up for about 10 seconds.
❑
After the engine has warmed up, drive the truck as you normally would. If the engine seems to be running rich (i.e., not reaching
maximum power), lean the high speed needle valve about 1/16 of a turn at a time until the desired setting is achieved. Always make
sure that you run the engine slightly rich - you want to be able to see a faint exhaust trail at all times.
SETTING THE LOW SPEED NEEDLE VALVE:
❑
Start the engine and lean out the high speed needle valve as per the procedures above. Close the throttle until the engine slows
down enough so that the clutch is disengaged and the wheels don’t turn when the truck is lifted from the ground. Allow the engine to idle
for about 10-15 seconds.
❑
While holding the truck off the ground (making
sure to keep your fingers out of the moving parts),
quickly open the throttle in a short burst. If the
engine just stops running as soon as the throttle is
advanced, the low speed needle valve is too lean
and the engine is not getting enough fuel. With the
engine stopped, richen the low speed needle valve
about 1/16 of a turn (counterclockwise).
❑
Restart the engine and repeat the procedure above until the engine will transition smoothly and quickly. Very slight hesitation in the
transition is normal.
❑
If you quickly advance the throttle and the engine seems to be very rich during transition (i.e., lots of smoke coming from the tuned
pipe and very rough sounding), the low speed needle valve is too rich and the engine is getting too much fuel. With the engine stopped,
lean the low speed needle valve about 1/16 of a turn (clockwise).
❑
Restart the engine and repeat the procedure above until the engine will transition smoothly and quickly. Very slight hesitation in the
transition is normal.
❑
Now drive the truck as you normally would for a while to get a feel for how the engine reacts to throttle. Now that you know the proper
way to tune the engine, you can make slight adjustments to the carburetor until you are satisfied with the performance.
To keep your engine operating at peak performance there are some basic maintenance procedures that need to be performed on the
engine on a regular basis:
●
After you are finished running the engine for the day, pinch the fuel line to stop the engine. This will allow the engine to burn any excess
fuel out of the crankcase.
●
Remove the air filter element and wash it thoroughly in warm water and a small amount of liquid detergent. After it's clean, allow it to
dry, then reoil it and install it back into the air filter housing.
●
Remove the glow plug from the engine and squirt several drops of high-quality after-run oil into the glow plug hole. Pull the pull-start cord
several times to distribute the oil throughout the engine, then reinstall the glow plug. The after-run oil will prevent the inside of the engine
(especially the crankshaft bearings) from rusting.
KEEP IT SMOOTH
Loop four nylon ZIP ties around the
corners of the engine's cylinder head,
making sure that the ratchet portion of
the ties are up toward you. When your
truck flips over, the ties will prevent the
cylinder head from being scratched
and gouged.
BASIC ENGINE MAINTENANCE
●
Clean the outside of the engine using a heavy brush and nitro
car cleaner, then dry the engine, using a rag or compressed air.
●
Periodically check the condition of the clutch to check for wear.
●
Periodically oil the clutch bell bearings.
●
Check the engine's cylinder head bolts and backplate screws
after each day of use to ensure that they're tight. This will
prevent air leaks from causing erratic engine performance.
To get more power from your engine you can use fuels containing
up to 30% nitromethane. We must caution you, though, that
once you run the engine with increased nitro you may not get
satisfactory results if you decide to go back to a lower nitro
content. Also, if you use fuels containing 30% nitro, we
suggest adding a .10mm head gasket (# 148418) to lower the
compression ratio. If you don’t lower the compression ratio, overheating and
erratic running will likely occur.
PLEASE READ IF YOU'RE USING 30% NITRO FUEL