motor???

http://www.amazon.com/Lifan-1P52FMI-K-Engine-Complete-Motorcycle/dp/B004Q1Z8JM/ref=pd_sim_sbs_auto_1 4 speed integral gearbox/manual clutch, 125cc, & at that price? Any idea of how one of these would do on a mini? I've heard absolutely stellar things about Lifan, and I might be...

Hi I recently purchased a "raptor" off of eBay. I of course bought the motor as is and won the auction at a very reasonable price. Anyways the motor looks pretty legit I haven't fully opened it up but I can see quite a few places that machine work has been done on it like where the valve seats...