How to Build Gas Bicycles

Whether you've decided to "go green" and ride your bike more or save money on transportation, or you want to ride your bike but just can't take those hills, putting a gas motor on your bike takes all the excuses out of not riding. Turn your bike into a motorized gas scooter in just an afternoon, using any of several simple kits offered online and in stores. They all come with detailed instructions, each a little different from the other.

Things You'll Need

  • Bicycle
  • Loctite
  • Old bicycle tubing
  • Scissors
  • Thread adhesive
  • Sprocket wrench
  • Plastic zip ties
  • Engine oil
  • Teflon tape
  • Tank liner coating
  • Spark plug wrench
  • Screwdriver
  • Bicycle engine kit
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Instructions

    • 1

      Nestle the engine in the “V” of the bicycle and decide where you want to put it. Cut out a piece of old bicycle tubing and wrap it around the part of the bicycle where the engine will be attached with the mounting brackets. This will greatly reduce vibration and protect your bicycle from scratches. Attach the engine to the seat tube first, then the front mount. Use lock nuts or Loctite to prevent screws from loosening due to vibration.

    • 2

      Use 12- to 14-gauge spokes on your back tire for longer life of your motorized bicycle. Pay attention to true alignment with the engine drive sprocket. Fit the sprocket over the back hub in a perpendicular plane with the axle. This will keep your chain from falling off. Follow the detailed instructions that comes with your engine kit for sprocket installation. Each kit is a little different, and your bicycle will be uniquely fitted.

    • 3

      Mount the ignition coil on bike frame close enough to the engine to attach the coil wire to the spark plug. Keep it away from the exhaust pipe to avoid heat damage.
      Attach the color-coded coil wires to the corresponding colored wires coming from the engine. Attach the engine-kill switch to the handlebar, using the kill switch mount. Attach the kill switch wire to the white wire on the engine.
      Secure wires away from the exhaust pipes with plastic zip ties.

    • 4

      Attach the clutch lever to the left side of the handlebar with brackets provided in your kit. Attach the cable end to lever. Route the clutch cable according to your individual kit’s instructions to the engine. Cut off excess cable at the clutch handle.

    • 5

      Check to make sure the air cleaner screws are tight before installing engine. They can come loose and wreck your engine. Attach the throttle cable to the carburetor throttle slide according to your kit’s instructions. Install this cable inside the carburetor. Mount the carburetor as level as possible on the engine intake tube with the clamps and screws. Install the twist grip throttle on the right side of your handlebar end.

    • 6

      Coat the inside of your fuel tank with a tank liner coating (This can be bought from motorcycle dealers). Attach the fuel petcock to your gas tank, using Teflon tape on threads. Mount the tank on your bike's top crossbar with brackets and nuts
      Attach the fuel line from your tank to the carburetor.