I've got a 2004.5 Sportsman 400, and when I'm riding along in High, if I apply full throttle, the engine starts to sputter and it seems like its dying (this starts to happen at around 40 mph). If I releases the throttle a little, it starts running fine again. Does anybody know what might be causing this?

BTW - This is the only problem I've had with it so far - an awesome machine otherwise.

Isaac

 

I saw there was a lot of grass in the radiator, so I cleaned that out. Then I checked the air filter, and it was just a little brown so I put it back in. After I did that, it will run okay at full throttle part of the time, but it still wants to sputter at full throttle some of the time. Does anybody know of anything else that might be clogged up that could be causing this?

Isaac

 

Ok, I was playing around with it again this morning. I took out the air filter again and cleaned the fabric pre-filter element with soap and water, dried it, put it back on the filter and hooked everything up again. I took her out in high, and I sustained full throttle without any problems. This is the first four wheeler I've owned, so I guess I gotta get accustomed to the maintenance procedures.

Isaac