Well, for one thing, the picture you posted is not a bicycle, got no peddles. Larger four strokes can and have been used but they require trade-offs most of us don't want. They are big, heavy and have a very low rpm range.
And yet that is teh supafly. I would weld up a wide crank,eliminate the jackshaft and install a belt ring via spoke mount on the left or weld a rim next to the wheel for a belt and a larger drive pulley by the engine for good gearing. That gearing looks pretty tall. I bet it goes,man cuz you had it just idling and it was going pretty okay. What's top speed?
And that ringtone is teh cool too.
The being able to pedal is important for it can deter you from police intervention. But it would be hard to convince anyone that's a 50 cc lol!
And what up with the front brake no rear brake?
yea gearing is tall i had it doing 84 km/h but if i had more space i think 90 would be about its limit.
i have now fitted a left hand foot peg
i also tryed a three speed hub and it went very well
ive been pulled over for speeding and the officer told me that it was totally illegal which i knew but its so fun slow reving speed is so soothing ive had the grube 2 stroke kit and hated the revs, vibration , smoke and smell
ive increased the rear sprocket size so take offs are a lot smoother and top speed is now 70 km/h iam also working on legal versions honda 35 and subaru 25cc
ok introduce myself iam currently in australia but also live in california hollywood and am also italian
ive been building bikes with engines since i was 15