Re: MX650 mods?
Aproldan: you're right about this motor as well..referring to adjusting the timing on it. You would normally have to redrill new mounting holes if you rotate the end cap by itself. I marked the motor end cap, center case and front cap with a silver Sharpie marker as a start reference. When I advanced the timing, I took the motor apart and rotated the center section then re-installed the caps to it. You only have certain spaces between the magnets to use for the screws that hold the end cap. But it works without having to change how you mount the motor if you play around with it.
All that said, I barely gained a mph when I advanced the timing. So I'm still "putting along" at a measly 29mph after quite a bit of runway. The motor was much warmer this time around too.. I think I'm going to put the timing back to stock or even max torque, go back to the 11-tooth sprocket and run at 48v for an overall fun and reliable bike that should last for awhile.
As for the speed stuff, I'm going to look for a new project and start fresh. I'd like to use a frame from a mid-size gas bike and some serious power for a sure-fire 35+ mph all day if I wanted it. Part of the fun is goofing around with modifications. Once you learn from the experience, the performance envelope can be pushed further with more research.
Aproldan, again I seek your wisdom. Are there any 2000w motors out there of decent size that would be suitable for such a project? I know brushless motors are expensive, but have you found any that seem relatively close to being reasonable or is Etek the final answer when it comes to big HP electric stuff?