I completly rebuilt my 05 trx 450r and it has smoked everyone at our local drag trax..i have raced it maybe 8 times for a period of 6 races each time and there is no competion now i cant beat someone walking,,i can feel the power loss in it,,the only thing ive done to is slip on, 11.5.1 piston, new kibble valves and new k&n filter,,the rest of thr internal is brand new oem but thats it and it got less power than in the beginng ..
where did it go?

 

Shaft seals replaced?.