This scooter was originally an electric Sharper Image scooter. It had a range of 6 miles, 9 mph speed, and 2 hour recharge time for the NiMH batteries.(pic of battery and motor below)
I needed a scooter with more torque and power because I live in a hilly area.
So, I started some research on retrofitting it with an engine, coming across this site (thanks tzi ).
The first engine I bought was a Weed Eater 18cc trimmer. This engine would have been OK except it had no clutch, so starting it would be a problem.
When I was modifying the flywheel to adapt a BMX freewheel, I broke the crankshaft trying to thread it (see pics of engine below). So, I bought a 14inch 33cc Poulan chainsaw.
I was going to go ahead with this engine, but I had a problem removing the clutch so I could mount a freewheel on it. Also, the electronic ignition is not mounted directly on the engine, so I would have to cut up the plastic on that side of the engine. The advantage of this engine is that the engine is very easy to mount, with 4 bolts coming down from the cylinder, holding the whole engine together.
One day I came across a pawn shop. They had a 4 cycle trimmer made by Ryobi, and it was never used and in perfect condition. It is a 26 cc engine and has a clutch.
I bought it for $129 and immediately started work on adapting it to mount on the scooter. I bought the aluminum and steel from Home Depot, and bent it into the form it is now (in the pics). I mounted a freewheel on the clutch with a compression fit bolt to keep the whole thing together. I also put a longer throttle cable on the engine. I bolted the whole engine to the scooter, and it looked like it looks in the pics.
The scooter has 4 inch wheels, and I have a chain drive system, with a 22 tooth sprocket bolted to the rear wheel, and a 17 tooth freewheel on the engine's clutch.
I know the ratio is too high, so I'll be buying a 13 or 14 tooth freewheel (I'm burning my clutch with my current setup).