hey guys, this is my first time at this forum, firstly i'd like to point out that after reading a few threads everybody here seems cheery, helpful, and most of all supportive. This is the second bike i've built, the first one was a rather poorly strewn together cacophony of parts. I sold it shortly after building. It's a Huffy cruiser with a 70cc China engine. Generic, haha! Nothing special but it is alot better than my first boneshaker. Everything feels solid. I'm 16 and work full time so i don't have a lot of spare time to work on it but i just got it finished today. Just wondering, sometimes when i get into the high revs it seems to lose a lot of power and sought of splutters. It also vibrates like nothing i've ever seen before. I've read this is because the chinese just chuck a bigger bore ontop of a 49cc crank, but i'm not too knowledgeable in this area. thoughts?