I called tomberlin today and they said a topend rebuild kit was $150. A little pricey for a chinese motor. So I hopped on ebay and saw GY6 150cc rebuild kits for around $75. I was wondering if all GY6 motors use basically the same pistom and cylinder. I saw that there was two different cylinder designs aswell as two different head designs (A and B). I guess all I'd have to do is take the plastic cover off of the motor and see which kind I have. I checked on SYC and their carb jets were $8 a piece! I also saw a 28mm GY6 complete carb rebuild kits with jets included for around $20 shipped. The jets in the picture looked just like the ones that came out of my carb with the exception of one (it was the jet with the three tiny holes in the side of it) this one in the picture had 2. Heres a link to the carb kit.
http://www.gy6150enginepartswholesal...s-p-14117.html