How to Build a Moped With a Chainsaw Engineby Chris Moore
A chainsaw engine can turn any kick-power scooter into a motorized vehicle. While you can simply make a stand-up motor scooter with the engine, adding a seat along with it can turn it into a full-fledged miniature moped. This is a complex and risky project, so be warned that you likely won't be able to use any of the pieces individually again, if you can't get your finished scooter to work.
Take a small, 2-wheeled, kick-powered scooter. You need a scooter with inflatable tires because hard wheels won't handle rough surfaces well and will be dangerous at the speeds. It should also have hand brakes to help stop the machine easier and handlebars with an adjustable height.
Prepare the chainsaw engine by removing the chain and bar from the crankshaft. You can also remove the centrifugal clutch from the crankshaft as it will make it easier to attach the needed bicycle chain to the engine.
Bolt a sprocket onto the crankshaft. If you didn't remove the clutch, attach the sprocket to the clutch bell. Bolt another sprocket onto the scooter's rear axle. Place the engine on the scooter's platform and line up the 2 sprockets together. Once you know where to place it, bolt the engine to the platform after drilling holes in the platform and the engine housing.
Connect a bicycle chain to the 2 sprockets. Use an extractor tool to remove as many chain links as you need to tighten the chain around the sprockets.
Add a seat to the scooter. You'll need a bicycle seat with the longest seat stand that you can find, plus a flagpole floor stand that the seat stand will fit in. Bolt the floor stand to the scooter platform. It must be long enough for the seat pole to fit securely in with no risk of coming out. It is best to attach a tightening brace similar to one used on a bicycle seat.
Test the seat's height in proportion to the height of the handlebars. Adjust the handlebars so you can comfortably hold them while seated.
Connect a method of regulating the gas flow to the engine to control the engine power and scooter speed. You can attach a hand accelerator from a dirt bike to one of the handlebars and wire the accelerator to the engine's on/off wires. You could also wire a small foot pedal to the on-off system and connect the pedal to the platform.
- close You should leave the centrifugal clutch on the engine if possible, especially if you use a "2 stroke" chainsaw engine that requires adding oil to the gasoline. Without the clutch, the motor will burn out if you do anything such as coast downhill, because you are running the engine without the fuel-oil mixture lubricating it.