Growlbear's Scooter
I just finished this rig with a Sturmey Archer hub
laced into a 12" wheel. It does 18 MPH in 1st, 28 in
2nd & 40 MPH in 3rd. This rig is very versitile and
quick.

Engine - Neoprene mounted 39cc Husqvarna 2 stroke from a brush cutter.
Frame - Home built 1.25 x .060" steel tube.
Tires - 12" scooter.
Primary drive ratio - #35 chain 1:2.5.
Final drive ratio - #35 Chain 1:4.5.

I have an improved version in the works.
I also have a complete set of plans in Autocad .dwg or in .jpg format.