The motor is a 4-stroke tecumeh 4hp with the governor removed.
I added a performance air filter.
It still has the stock muffler which is extremely quiet, and much less annoying than a 2 stroke, but i do intend to put on a straight pipe (only about ($20).
The rear kart tire is 12" tall by 6" wide and the front is a kids bike rear 16" tire with a disk brake hub welded on, Thats right front disk brakes.
Chain driven with a gear ratio of 5.00.
It seems a bit slow off the line but still takes off faster than most go-peds.
The top speed, measured by driving beside a car, is 42 miles per hour.
It has a rear live axle like a go-kart and a band brake operated by a rear foot pedal.
Total cost to build was about $300.
I used Dupli-colors' Mirage spray paint which changes color from red to blue on the motor, rims, and handle bars. It really sets it off with the chrome.
The motor is mounted just high enough for the air cleaner and muffler to clear the rear tire. I wanted the center gravity to be as low as possible for better handling and it does a great job of it.
Also It has a twist grip throttle like a motor cycle.
It took about 40 hours of labor and research to make.
If anyone has any questions on how to make one I still have the plans in autocad and in sketches. Please email me at firstname.lastname@example.org