My sportsman 600 runs very rough at an idle in cold weather. Seems to be intermitent. It will do it cold (more often) and warm. I can pull the choke to keep it running but it is still running rough. If driving at high speeds it will back fire when throtle is released. Sometimes if I shut it off for a few minutes it will clear up. I use my quad all year round and am frustrated. I know of other people with this problem and wonder if it is just the bikes or is there a fix? My dealer can't seem to help me.

 

its wiered that the problem is intermitent...i would sya #1 clean out the carb well. 2. your backfireing and running junky because its cold outside, the air is more dence causing you to run a bit lean. this usually clears up if you richen your piloy jet a bit.

also try bumping up your idol a bit for winter

 

I'v cleaned the carb and am going to put in new plugs. The dealer put in a 157.5 main jet and adjusted the pilot jet. My stock main was 155,not that the main jet affects idle. It was a service bulletin.

 

I had a 2004 600. My main reason for selling it was they run rough in cold temps. I plow alot so it was very frustrating. Im afraid that is just how they are. 2 of my friends also had the 600 and they both did it as well

 

That sucks. If I plug it in it seems to help.

 

plug what in?

 

The block heater

 

That will definitly help with start up. Mine used to run fine some days and crappy others. Like you said it would even run different if I shut it off for awhile. I can understand your frustration!!

 

wow, idk that it was a prevelant issue with the 600 series. if rejetting dose not help then idk what would

 

i had to mess with the needle valve and it helped some but not a cure all....it doe suck!!!