Has anyone performed a big bore kit on a gy6 150? I need to replace the top end on my Roketa 150 atv and I have been looking at doing the 59mm top end. From what I have read, this is the biggest you can go with out boring the cases. Any info can help me decide.

 

Is there anybody out there? This is for my 14 year old daughter.

 

I certainly don't know.

I no one else chimes in, I would consider posting the same question at www.buggynews.com in the 'engine clinic - mini off road buggy' section. This is a buggy site - not ATV - but the same engine is used extensively on buggies. There are a lot of knowledgable people there, and several GY6 parts vendors. They have (so far) been very tolerant of ATV intruders.