I was thinking you could short some of the windings, but that would be hard to do reproducibly for each pole and probably wouldn't hold up too well either.
It's gear driven and we have maxed the gearing out so far but unable to increase Heat or RPMS we are trying to generate about 150 Degrees in a 4-5min time span but unable to do so.. Best we could achieve is 120 Degrees so far:
As you want to increase the RPM only, it seems you need to change the controller board. I am guessing that this is what you have been working on, but your posts are very cryptic. A bit more elaboration of what you have done so far might help for further help. See this wikipedia