48cc/49cc Questions

[FrizzleFried]

(1) - I assume 48cc/49cc engines are advertising their actual size (versus the 80cc which is a 66cc engine)? Is this a correct assumption?

(2) - What is the performance difference between the 49cc and the 66/80cc? I'm considering building a bike for my soon-to-be-thirteen year old so we can go on rides... illegally of course (i admit it... but I'm in a pretty rural area and could get away with it)... He's pretty tall coming in at 5'5" already... probably about a buck twenty fiveish... maybe a little more. He's none-too-experienced with motor anything (by the time I was 12 I'd "mastered" the powerband in my 1979 YZ80... should I bother with the 49cc or go right to the 66/80? I mean, I COULD retard the 66/80 a bit to keep the speeds down if it got me nervous... right?

 

[Chainlube]

The 49cc is a good motor. I put one on a folding bike. It has 20" tires and is pretty quick little bike with lots of hill climbing torque. You can look over a few of the tricks I had to perform to make it all work in this thread.

Auto-Mini

Started this build a couple weeks ago just to see if. It's coming together. The exhaust header was a real head scratcher, it was coming off the engine right beside the hinge. I still want the bike to fold when it's all done. Just a sample, stay tuned. 50cc bust or boon.

motoredbikes.com