i only have three miles on mine so far,it does seem to be alittle rougher than my 99sp.i noticed the clunk also on takeoff,does the white spring make it rev higher on takeoff?? i had to have a green cause i do alot of deer hunting and it blend in better.boy this new motor rocks!! ive only floored it a few times and it really walks. hey lets go GRIZZ hunting!! lol