Snowmobile Repair: Bogging, electrical fault, wise idea

Question
I have an 86 phazer, 480cc, yamaha.  The problem I am having is after it gets warmer.  It bogs down under a load but if holding the gas down long enough it eventually takes off. Reacts worse with a heavier occupant...get's worse the hotter the machine is.  I was told by a mechanic who heard the symptoms that it was a belt problem.  I haven't replaced the belt for quite some time...I was thinking though, that is was something electrical.  I've messed with the carbs leaning etc with no results (pretty sure it's not a carb issue).  What do you think?

Thanks,  Jason D.

Answer
Hello Jason,

  I highly doubt that it's your belt, but it couldn't hurt to buy a new one, they are availible at www.denniskirk.com for a very reasonable price. You are correct I think, about an electrical fault. I would suggest replacing the plugs with NGK BR8ES gapped at 0.028 inch. If you don't have trouble with fouled plugs. You may want to have your CDI tested at your dealers, too. I noticed that you had mentioned that adjusting the carbs didn't seem to help any, if the sled has sat around for over six months without the gas being drained or stabilized, the carb can get gummed up and it won't respond to any adjustments. If that's the case it would be a wise idea to rebuild the carbs ( about $20.00-40.00) I hope this helps. Let me know if I can answer any other questions you might have. Good luck with the sled! Arcticatman