I have a 2005 Sportsman 800 EFI that has started to miss when it gets hot - only. You can hear and feel it dropping a cylinder at idle and continues to get worse the wamer it gets. If you stay at a decent speed (better air flow) this doesn't happen. It does continue to miss under acceleration the warmer it gets. Once it cools off, it runs great for awhile.

I have changed the spark plugs (fun job!) already and checked the plug wires, even moving them around when it's happening, with no luck. The plugs seemed to solve it for a few rides, then it came back. Also ran fuel system cleaner through with fresh gas. It has approx. 2500 miles.

I was thinking it may be the ignition coil causing this, has anyone else had (or heard) of this problem?

Maybe it's time for the new 09?!


Thanks for your help!

 

It could be that, or your fuel pump is dying.

 

Thanks for the suggestion, I'll check the fuel pressure. Are fuel pumps a common problem on a 2005 800 EFI?

Thanks again for the help.