i am will to bet that the service manuals maximum horsepower rating of 27kW(37PS) @7 500 rpm is correct but ....but i bet this is at the crankshaft not the rear wheel ......my cr250 says 52 horsepower on the title but in the mags its only 45 at the wheel.so you both might be corect.why is this thread closed?http://www.dirtrider.net/forums3/showthread.php?s=&threadid=75507