Scooter Frame

• Locate a scooter in good condition, without rust or apparent structural damage. Purchase a new scooter, or pull together parts from various bike stores and junkyards if you're so inclined. If you want a more advanced scooter with the ability to accelerate, you can pick up hand brakes from a bicycle store, as well as wiring. You will eventually attach this to the "throttle" of the motor.
  
  

Motor

• Make sure the chain-saw motor still runs. Remove the plastic parts and blade: Cut off the metal blade itself, as well as removing the chain. Weld the motor onto the rear of the scooter using scrap metal so it sits just above the wheel. You will also weld a "clutch" to the axle of the back wheel; this will consist of a metal bar, with a ball or sprocket attached to it that will connect with the motor and ultimately turn the back wheel. The ball or sprocket attaches to the motor simply through friction, rolling both with and against the spinning motor. Additionally, you can attach a gas tank to the top of the motor that will pour into the motor's internal gas tank.
  
  

Key Components

• Scooters.tziworld.com recommends that you test which direction the motor spins before welding it to the scooter. The motor may turn the opposite way you expect, which will make your wheel spin backward. This will make the "clutch" necessary; the ball, wheel or sprocket you attach to the back axle will help reverse the course of the motor, causing the scooter's back wheel to spin in the appropriate direction.
  
  Run a thick wire from the motor's internal throttle to the handlebars of the scooter. Install a bike brake handle, which will have enough torque to pull on the motor's throttle, and attach it to the wire.
  
  Finally, change the scooter wheels themselves. The clutch may "slip" on the scooter's original wheels. Replace them with solid rubber wheels in a smaller size, which will prevent the clutch from slipping.