HELP, Making a Bike From a Helio Darkside EZM

[Galactis]

The Helio Darkside EZM,
http://heliobikes.com/store/Motorized-Bicycles/4-Stroke-Bicycles/Helio-Darkside-EZM-p261.html

Shown above... in the link...
Is what i have to start with.
I want a larger motor, i wanna go about 50+ MPH
How can i accomplish this?
Im willing to spend up to 500, but not more on a larger engine.

 

[bideronit13]

You could keep the bike and the engine if the engine is either a Honda GXH50 or a Hua Sheng 49cc. Buy a sickbikeparts 4 stroke shift kit and adapt a 7 speed rear wheel.
I'm actually trying to go 73mph with a Honda gxh50 and I should have the results in a week or so.
Check out my profile if you want.
Read up at sickbikeparts.com they know what there doing.
You might even be able to sell the stuff you not going to use from heliobikes on one of the threads around here expesially the ezm tranny.