QuestionHello. I am trying to get the above mentioned Sled running. I have done everything I can think of. I have put Fuel down in the Cyclinders to try to get it to spark over and it still doesn't. The Carburator is fine. It has Spark. Can a weak Coil or CDI still throw out spark if it is no good? How do I check the Coil? cdi? if the Sled doesn't start..How can I check the timing? I'm completely frustrated. Also when I pull it over about 10 times or so after putting the fuel into the cyclinders, It will pop over and die, Sometimes it yanks my arm off and the motor seems to want to turn the other way? What is wrong with this thing? Please help.
AnswerHello Charlie,
I've been there, with the sled not starting. The comprssion could be bad on the sled. Try placing your thumb over a spark plug hole and having someone crank the engine over, make sure the wire is grounded! If it blows your thumb off, it has good compression. Also, a compression guage would be even better. The only accurate way to check the coil or CDI is to have it tested at a snowmobile shop. You might want to try NKG BR7ES plugs, they will keep any fouling problems down. On any old sled, if the ignition system is producing a weak spark, you probably won't get it started, and yes they can put out a spark, even if they are getting to the point of being no good. Have you tooken the carb apart and checked the inlet needle valve? Those are prone to sticking/varnishing, and causing a no start. You can get replacement parts at www.mfgsupply.com and www.alssnowmobile.com . Here is a john Deere site that might help: http://ryan55349.tripod.com/johndeeresnowmobiles/index.html
Here is the basic FAILURE TO START guide lines, I hope you find them helpful.
Remove and examine spark plugs. If fuel is reaching the cylinder in the proper amount, there should be an odor of gasoline on the plugs if they are cold. Too much fuel or oil can foul the plugs causing the engine not to start. Fouled plugs are wet in appearance and easily detected. The presence of fouled plugs is not a sure indication that the trouble has been located, however, the engine might have started before fouling occurred if the ignition system had been in good working order. With spark plugs removed, hold wire about 1/8 inch away from an unpainted part of engine and crank sharply. Be sure to check both plugs and wires, and also ground the other wire while check for spark. the resulting spark may not be visible in broad daylight but a distinct snap should be heard as the spark jumps the gap. If carburetor and ignition were both in apparently good condition when checked, examinee other elements of the engine such as crossed plug wires, or a fuel delivery problem.
DIAGNOSIS:
If the presence of fuel was not apparent on the plugs and the spark is good, systematically check the fuel system for the cause of trouble. Possible causes of lack of fuel could be: No fuel in tank, Frozen or clogged fuel lines or filter, fuel pump impulse line disconnected, Damaged or frozen fuel pump diaphragm, Carburetor dirty or improperly adjusted, including a sticking inlet needle. Also try removing the muffler and checking for clogged ports. The proper plug to this sled is: NGK BR8ES,. but if you have trouble with fouled plugs you may want to use the NGK BR7ES. I hope this helps you, and let me know if I can answer any other question you might have. Good luck with the sled! Arcticatman
