I have an 2001 mxzx 440 and the other day I noticed a bog out on the trail. So I brought it to a local pond and when I come out of the whole it only tacks to 8200 but then immediately drops to 7000 rpm and then slowly works back up. After alittle while of tring to find the problem the sled would climb from 7000, hit about 8000 rpms and the the tach would start jumping like it hit a rev limiter. The sled seems to be running fine on low rpms, but it seems to me like it is running out of gas. The plugs are running about a light brown. I went through the clutches and throughly cleaned them. I tried a few different setups including helix changes and springs. It made no difference the sled just seems to be lacking the power. I tried turning the clickers up on the front clutch as well but sled still only tacks to 8200 instead of 8500 rpms. Any suggestions would be very helpful because I have run out of ideas.