i put a brand new cheezy pk80 on my bike yesterday, was able to run about half a tank through it and so far at half throttle it is as fast as my old motor. To be fair the old motor was burning the piston and a slight score on the cylinder, it can and will be fixed and a new piston in and it'll be great. i can't wait until this motor is broken in then i will get a different exhaust, i had to use my stock NTC carb to get it running, come to find out that the jets on the new carb were unscrewed and floating in the float bowl. i havent put it back on to test just yet because i changed the intake as well.
also i have this axle and i was wondering if anyone knows if there's other sprockets i can use for it, maybe a slightly smaller one, or will i have to modify one to work? http://www.bikeberry.com/engine-kit-...-axle-kit.html