I have a 2011 Kawasaki KFX 4 stroke 50cc, I have put a Wiseco 80cc piston, cam and head kit on it, and it runs great. My son got a new ATV and so I am selling this one, it is a 50cc chassis but the 90cc and the 50 is the same for Kawasaki just tire size difference. It has a ECU governor from factory so it runs about 16mph, you can buy a unrestricted one on the internet, this thing has alot of torque a donut machine, it looks near perfect and runs great. I would let go for 700.