How to Make a Really Cool Gas Powered Motor Bike

make a cool bike that make a great speed of 20 to 30 mph ( depends on CC of
engine too )

Materials:

fishing line
a box of straws
a small box
a Bike with hand brakes
a bike rack that connects to the seat   
a couple different sized chains
and a 49cc to 100cc engine

tips:
if you get a chain saw engine it will have lots more torque and power,
if the engine has a clutch it works better   

I mount the engine ( green ) on the rack of the bike
with the gas ( red ) tank strapped on to the box ( yellow ) strapped to the rack ( orange )

The throttle on the engine should be near the carburetor and it's a little lever that I tie fishing line to

I tape straws ( blue ) on the side of the bike running fishing line through them,
the hand brake for the front tire disconnect it from the brake the tie the remaining end of fishing line to the brake handle

Take a couple chains until you find one that fits tightly and snugly 
 

In the picture it is running from the engine to the back gear 

Pull the handle with the cable to start the engine then test your throttle by puling on it like a brake

then test ride