[theword]

I have a 1996 polaris ultra 680. I have cleaned out the carbs and all plugs and wires are new. I have adjusted the carbs to the way that I was told by someone that I really didnt trust. I was loading my snowmobile last night and the throtle responce was good from 1900 rpms to 4000 rps. Than anything over that it would back fire and then bogg down. I have a fealing that it is to rich. It runs really good at low idel and starts on a half of a pull or a flick of the starter. I was wondering if I should take it a little leaner. Now there is two screws on the carbs. One is a small one close to the front of the carbs. The second one that is on the carbs is the big one on the side. I think that the big one is the lean or rich one and I should turn it in about a 3/4 of a turn. If anyone can help me on this please help! I will be making sure that the spark plugs are good as well since the backfiring.