jr.ink said:
Hey Rich what can you tell me about the Big Gun Rev boxes for a CRF250?
I don't know anything about it. Big Gun is a good company but 4 horsepower sure sounds like a lot from an ignition system. I'd need some serious proof before I would believe that claim.
Getting the engine to breath better is generally the best way to take advantage of an increase in bore size. Whether you do that with a cam change, porting, or both, getting more air in and out of the engine is a good place to focus your attention.
One thing is for sure, given how heavy that Rick Petersen piston is you don't want to raise the rev limit in the engine, or where it develops peak HP. If anything you should be looking for ways to lower the rev ceiling, and the peak horsepower rpm. High rpm and heavy pistons are a really bad combination, and that piston is
HEAVY.