I was north this last weekend U.P. of Michigan, the first 2 days sled ran great, friday night started bogging, had a hard time geting over 60mph. It would clear out for awhile than go back to bogging, started good and would idle good, never quit but had a hard time going, used more gas than the 800 and 900's. Changed plugs and used same gas as everyone else. I pulled plug wires on each plug while running and one side would spark about a inch and a half and the other only about half an inch, so I thought must be the coil. when I got home I checked my other sled 2001 500xc and the spark was the same, whats up with that? What should I check next?

Thanks for any advise,
Steve

Maybe sacked out clutch springs especially the secondary spring if its not backshifting.

What does anyone think about the coil? does the coil wires both spark at the same time and why a longer spark on one plug wire?

Shouldn't be...spark is spark. I'd pull and trim the ends of the wire with the weaker spark.