K, my girlfriend has a 2002 Yamaha Beartracker, now I ride with her and a buddy of mine on some hard trails, I put some wooly booger looking tires on the back not too long ago, now today we were in a big thick mud bog, we were actually making it through, second gear, the motor was lugging and spinning tires a little bit, were were hardly moving, 1st was too low, and third was waaaay to high, now I got it going, and I know we were overheating, but I wanted to get to the otherside, we were already falling behind, I looked down at the whole headpipe was red hot, so I knew things were getting extreme down there, I shut it down and let it cool for about 20 minutes, and got going again, now we rode for about 10 more hours today and want to get her maintenance done this week. I'm going to do the oil and filter, what oil should I be using ?? I'm going to change the plug, set the valve clearance, and i want to change the gear oil, as we had the rear end in water almost all day today.... I guess just drain it, and fill it back up till it comes out the hole.. what kind of oil to use ?? Just some 90wt gear oil ?? also, the auto clutch seems to be slipping a little more than it should, how is that adjusted ??? Thanks guys.... thanks, any thing i'm missing ?? Thanks guys....