I have an 06 400 auto. I put an epi clutch kit in it for stock sized tires. I have 25-10-12 mudlite xl's on the front and 25-12-12 xl's on the back. The bike can't seem to get out of its own way. I didn't think putting same size diameter tires would rob that much power? Anyway would a over stock tires clutch kit be better or should I go back to a thinner tire? Also Would a slip on exhaust (the one they sell at speedwerx) give me noticeable gains in performance? Its a $250 dollar investment. Also in low gear (stuck in the mud or going up a steep hill ) how much throttle can you use ? Thanks for any help or input.

 

Sevenmag,

I really don't think it's the tires that are the problem. The width of the tires shouldn't affect the performance of your atv. If you still have your original tires and wheels, try putting them back on and see if you've still got the problem. Good luck!

toe

 

Rule #1 of hot rodding and performance mods, "Do one at a time, so you will know which one is the bad mod."

 

If you are going to modify your ATV I have to agree with what bear said.

Also, the 400 AC engine really wakes up more with about 500-1000 miles on it. I guess by then everything is REALLY broke in a seated well. Prior to having to rebuild the top end on my 400 if I was carrying a tool box or tote of moderate weight on the rear rack and leaned back when I hit the throttle I could get the from tires off the ground. It surpeised me when I first did it and it made me a little more cautious as I did not want that heavy machine coming over on top of me given the right conditions.

SJ

 

guys i ride with have the same tires on ther 400's and dont have any power loss. they increased in handling and mud though. id have to think something else is wrong.

 

Like the toehanus said earlier. You need to try the stock tires and fine out if it is the tires or the clutch springs. If you want to troubleshoot and skip the changes you made as a possible fault (not a good thing to do) then change the spark plug, check and clean the air filter and then drain the tank and carb and install new fuel (I mean fresh from the pump and not from your gas can)