Is it possible to bore a moto 4 200 (67mm bore size) to a 71mm bore size? What is the largest you can go without exessive engine noise?

 

i think 71. I'm geting my 225 bored out soon its at 70.5 so i think 71 is the most you can go I THINK

 

wiesco only offers 67-68mm pistons for the yfm 200's i was wondering if it was possible to run a 225 (71mm) piston somehow like re-sleaving or boring it out. looking for maximum power i can get out of my 200

 

i know you can only bore them out so much so talk to your lockal shop. I would see if there is a jet kit for the carb, and if so i would get it bored to 68mm with the jet kit and new k&n air filter and exhaust systems you should make more power. and if there is no jet kit you could ajust the carb needle it will put more gas in but more gas need more air.