1990-1998 Arctic Cat Snowmobiles Repair Manual, Page 65Get this manual
TROUBLESHOOTING
Overheating and Lack of Lubrication
If the engine is running rich, one or more of the following conditions may be noticed: aThe spark plug(s) foul oftenSometimes this condition has been masked by installing spark plugs of hotter heat rangebThe engine misses and runs rough when operating under loadcExhaust smoke is excessive when the throttle is depresseddWhen the throttle is open, the exhaust will sound choked or dullStopping the snowmobile and trying to clear the exhaust by holding the throttle open does not change the soundIf the engine is running lean, one or more of the following conditions may be noticed: aThe firing end of the spark plugs become very white or blistered in appearanceSometimes spark plugs of colder heat range have been installed which masks the problembThe engine overheatscAcceleration is slowerdPerformance flat spots are felt during operationThese feel like the engine is trying to run out of gaseEngine power is reducedfAt full throttle, engine rpm will not hold steadyELECTRONIC FUEL INJECTION