hey i have a 03 660 raptor i just put a wiseco high compression piston 11.1 and stage 2 hot cam in it. it always started great before but now it wont even crank over motor will hardly turn over. does anyone know if this is a common thing with this upgrade to them or maybe a problem with?. any help would be great so i can get to riding thanks alot

 

did you do any value work? Now your atv has higher compression may have to upgrade batt and starter, Did you adj values after decompression closed exh value?