You can hot rod any motor. But it takes lots of money, and four strokes in ATVs are so inefficient, its not worth it. Unless you are going to put a street bike motor in it, its useless. Although as Beech said, the technology is on the rise, it still doesnt compare to what you can do with a 2 stroke. Ever watch GP500 racing? Those are 500 cc 4 cylinders that are pushing 200 hp. But there is new technology coming, IE 03 GSXR1000, that has a showroom stock 4 stroke 988cc dynoing at 157 at the wheel, now that is impressive..

-Nick

 

I saw the dyno graph of a turbo, big-bore banshee that my dyno shop tuned. I believe it was between 160-170HP. At about 7000 rpms the graph shot straight up to the top. Never seen anything like it. Personally, I like the torque of a 4-stroke. It is like driving a 400 hp turbo 4 cylinder vs. driving a 400 hp V-8. But it all has to do with personal taste and what the intended use of the engine is.

RR1