I have a 1997 polaris sportsman 500. Does not have the engine braking system. Runs great but when going down hill and I let off the gas it backfires, it only backfires under these conditions. Anyone else out there have this problem with their machine?

 

I have a 96 with no backfiring, might try cleaning the carbon out of the muffler, just pull the plug and put your hand (with glove or rag)over the outlet and start it up and blow it out, might tap around on it this helps.

 

thanks for the advice, I will give this a try.

 

Another thing it might be is a intake leak, check the carb. Might be loose.

 

Is it stock? You might be lean.

 

Did you check throttle cable adjustment? If it has too much freeplay the ETC will cause the bike to backfire.

 

POLARDOGG,hit the nail on the head about the ETC switch being out of adjustment this will cause the machine to backfire every time when you let off the gas and the machine is coasting to a dead stop.

 

all excellent suggestions guys, thanks for all the help, sounds like the ETC switch could be the culprit, I will work my way through this list.