FRAME: A little kids scooter with a home-made engine mount.
ENGINE: Briggs 3.5hp with milled head and porting job (done myself). UN-GOVERNED and POWERFUL.
DRIVE: Noram clutch to jackshaft (11:18) then jackshaft to wheel (10:40).
WHEELS: Original 12 inch Scooter wheels and plastic mag rims.
SPEED: I'd guess about 35mph @ 6500 rpms. I'll ask a cop to clock me next time I get pulled over.

This thing pops wheelies easily and will go off-road pretty well- it doesn't take bumps well though. I can do donuts in the dirt with this thing too- check out the last two pics.

Several people have asked me for plans so I drew some up and here they are. If anything is unclear to you feel free to e-mail and ask.

All the metal I used (except for the engine mounting plate and the jackshaft hangers) was 1 inch wide flat metal thingies. Braced here and there it's very strong. My 200 lb. neighbor stood and jumped on the mounting plate when it was done and it didn't budge. The only bug was that with the strong pull on the back of the mounting plate where the jackshaft was, the plate actually slowly bent down towards the wheel, loosening the chain. The plate also bent up between the two sets of legs. The solution to this is the pieces of metal that run horizontally under the mounting plate. Hopefully there won't be any more problems for a while. Attach a 5 inch long piece of metal to the back of the jackshaft hangers to keep them from moving side to side (that's what the angled piece on the back is in the main diagram). The only other tip that comes to mind is that when you cut the slots on the back legs don't cut them deep at first. The only way to adjust chain tightness on the wheel sprocket is to adjust how high the engine mount is off the axle. so cut the slots shallow at first and then when you're putting it all together, grind it until the chain is just the right tightness. I cut mine too deep and needed to make spacers to stick in there.

I plan on getting a 13 tooth Noram clutch to replace the 11 tooth Noram on there. There's two reasons for this- #1 it's got plenty of power but not enough speed and #2 I'd like a clutch with needle bearings. That way I won't have to risk blowing up the engine at full throttle and the clutch will last me longer (the teeth on mine are worn anyway).