hey mike, i have an 04 150 mine is very modified. i ran it on the dyno and made 20.4 horsepower. this little motor is almost uncontrollable now so its loads of fun. it will out run most cr85 mx bikes. go here for the motor goodies. www.powroll.com click on products, find your bike in the list and go nuts. the rev box will make good improvements. good luck