Towards the end of last season my sled started to bog after running for only 5 minutes or so. When this happened I would shut it down, wait 10-15 minutes or so, and then run it again just fine for about 5 minutes or so. Some people are suggesting that the engine coil is getting warm and then acting up. This is a sign of the coil going bad. Would you agree or suggest something else? Thanks in advance for your time.

This problem is tough to diagnose without some other information...
- How do the plugs look? Are they a nice tan color or are they wet or do they look like carbon buildup?
- Hows the compression in the cylinders? Do a proper compression test?
- As you run it and it starts to bog down, will putting the choke on or giving it a little trottle help the situation?
- A simple test is as you run it, and it , if you spray starter fluid along the seams of where the head gasket is and the case gasket is, does the motor begin to idle stronger? (BTW This is a head or case gasket blown out or leaking!)
- Have you done any recent mods to the sled last winter where the carbs air/fuel ratio were compromised? (ie - airbox mod, rejet, etc.)
- Lastly, have you cleaned the carbs anytime soon and or replaced the needles in the carbs?

I know its a lot of stuff, but any snowmobiler having problems needs to run through these tests to narrow things down so were not just shooting blind in the air so to speak! And for the engine coil simply getting warm or whatever, the coil is usually at a warm temp anyways, so ive never really hard of problems with this before!

Answer these questions, and then we can move forward!

550ss.... I appreciate your detailed response. Everything you suggest checks out ok. My answers below:

- Plugs are fine
- Compression is good
- No, choking or giving it throttle doesn't help
- No, spraying starter fluid along the gasket seems doesn't make it idle stronger
- No mods
- Carbs and valves cleaned before the start of last season

Does knowing this information help? Is there anything else you might suggest or does this point back to the coil?

Thanks again!

Have you added some "Isopropl alchohol" in case it is water/condensation build up.

How many miles on the fuel filter?

Dont overlook your primary clutch either,had this happen before.

Hutch, These steps are just the first steps taken in diagnosing a mechanical/engine based problem... Now because everything as of now checks out, Im thinking it in fact is now more so either an electrical problem or drivetrain problem like NEWBE stated. Go through the drivetrain and narrow it down...if it can run long enough to hit the throttle a bit ( ie just enough to have the sled move on the ground) without the sled bogging down immediately after, or if you loose power when you give it gas we can easily rule the clutching/drivetrain question out! (Also, dont lift the back end up to run the throttle bc this is like having the belt off the sled...there is no tension so to speak on the motor because the track is off the ground and not pushing the weight of the sled...this normally wont cause the sled to lose power if there really is a clutching problem...Make sense?) Now, as for the last situation...we have to narrow down some electrical...basically in the motor, if youre having electrical porblems, two main things on the sled come to mind...ignition module(which really never goes bad...theyre pretty bulletproof) or what you originally thought, the coil...now the coil will eventually go bad, but youll normally know if its bad even before you start the sled...try when you run the sled, you sometimes are able to get some readings with a volt meter... if you can get one close to the ignition module and then one at the coil and see if there are any ambiguities there...check your spark, pull the plug boot off and use a screwdriver and pull the cord (ya i know its the redneck way) see if you see a spark... should be very notcieable...if you really have to concentrate and stare, might want to start looking on ebay for a coil...best rule of thumb, some places are cool, but some are dbags, see if you are able to maybe find a used, even a new coil and throw it on to check if you sovled the problem or not then keep it if you do need it or send it back, ya they might piss and moan and charge a restock fee, but sometimes it even helps if they are willing to take a return! haha I know these steps are all pretty shady and low-budget/redneck style, but at the end of the day, they work and you just simply have to narrow things down...coils can also lose life time if they arent snug and they vibrate all the time...BTW any frays in the wires where they are coming into metal contact? Im ruling this out bc your problem is consistant! but again, it never hurts to check! Now that you did everything, and you cant find anything, id say coil too! but dont go buyin one till you rule other stuff out and you find the cheapest one! haha! safe ridin to ya

One thing not mentioned is the temp sensor. A common problem on the 01 sleds, not so much lately.
A faulty temp sensor can put the CDI in "protect" mode, retarding ignition until it bogs and sputters.

As for returning electrical components, most shops states that electrics are non-returnable...

How many miles should you go on a fuel filter? It seamed I have the same problem, but my power valves were full of black oily, gummed stuff. cleaned them sled ran great for the day next day I had to pull and clean them.