Engine has been sitting in storage for last 2 years, I just want it gone. Ran last time I had it on the kart but I could tell by turning it over by hand that the compression was pretty low. It will come partially disassembled so it could fit in the box, the exhaust can and engine mount will be removed. I am unsure on the bore size and have no way to accurately measure it. ENGINE IS SOLD AS IS AND NO RETURNS WILL BE ACCEPTED. PLEASE ASK QUESTIONS BEFORE PURCHASING.