How to Build a Motorized Scooter

Building a motorized scooter involves taking a kick-push manual scooter, similar to a Razor, and installing a motor on it to propel the scooter without manual pushing. This requires a bit of creativity and thinking to pick the right engine, determine how to secure it and then how to use the engine power to move the scooter. It also requires some thinking on how to accelerate and slow the scooter down as well.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Chainsaw engine
• Manual kick-push scooter
• Power drill
• Electrical wire, 18 gauge, black and white colors
• Wire crimping and cutter tool
• Nuts, washers and bolts
• Bike chain
• Bike chain tool
• Screwdrivers, sockets and spanners

Construction

1. Purchase or obtain a manual push scooter that already comes with a handstand for the front with brakes on it to slow down.
   
   If not already included, install bigger inflatable tires versus the hard skateboard type wheels you find on a smaller, Razor-style scooter. Choose bigger tires to ensure stability at higher speeds and avoid speed wobbles or crashes.

2. Purchase or obtain a chainsaw that you can disassemble. Remove the chain, bar and related sawing parts from the engine. Also, keep the cover and body around the chainsaw engine because this will help later as a cover and securing piece to the scooter.
   
   Use the engine housing to bolt the engine to the back of the push scooter and secure it. Line up the engine so that the engine chain pulley is fairly placed over your rear wheel and attached sprocket. Make sure to use the right size nuts, washers and bolts so that the housing doesn't crack when secured. Bolt the housing to scooter footboard to secure it on the scooter. If holes aren't available, drill them carefully with a power drill.

3. Use the energy from the chainsaw engine drive to propel the scooter. Modify the rear scooter wheel axle by attaching a sprocket to it. Then attach a drive system via a basic bike chain. Connect the bike chain to a pulley drive sprocket on the chainsaw engine. Measure how long the chain needs to be once wrapped around the rear wheel sprocket as well. Break the bike chain links with a bike chain tool and size the chain to span the distance measured. Remove the excess bike chain links. Reconnect the shortened bike chain links and complete the drive system. When finished, the chainsaw engine will drive the chain, which in turn drives your rear scooter wheel.

4. Plan for your handlebars to have attachments for the engine controls. Install a simple on/off switch to the handlebar. Then attach the throttle wire for the engine to the switch on the handlebars, and run it down the neck and back to the engine acceleration trigger. Confirm all wire ends are connected to the appropriate connectors on the chainsaw engine and the handlebar to complete the on/off circuit. Secure the wire insulation to the scooter body and handlebars via zip-ties to avoid snags. Add further protection by using insulation tubing so the wires don't get frayed or cut.

Tips & Warnings

• Propulsion via a chainsaw can be a misleading and powerful mechanism. Most people think because the engine is small it will be no problem to control. However, these little engines can move a modified push scooter at speeds upwards of 25 to 30 mph. Remember, they are originally designed to cut through tree trunks with significant torque. That's a strong and fast enough engine to get cause injury or an accident on the road. Always wear a helmet; knee/elbow pads are probably a good idea as well.
• It also helps to make sure you're aware of your local municipal traffic laws before going out on the street. Some towns and cities don't allow vehicles as small as push scooters on the streets. Additionally, there may be noise ordinances that could result in a ticket, since chainsaw engines can be very whiny and loud.

References

• Build a Gas Scooter : A How To Manual; Gas Scooters, February 2009
• Understand More Info About Motor Scooters and their Enthralling History; Bike Easy, August 2009.

Resources

• Motor Bicycling Information