I'm still new to all this. My first build is running without being able to disengage the clutch (I'm waiting on a replacement motor.) Even in this condition the bike is loads of fun. But recently I read on an Ebay vendor sight, that there is no 80cc engine. That the 66 and 80cc engines are one in the same. It was stated that the 80cc is a marketing stretch that 80cc is close enough to the 66cc so many vendors call it an 80cc. Is this the case? Don't these guys know what they are selling or getting from China?