pipes can actually hurt power if you get the wrong one. the 2stroke engine's performance is LARGELY determined by the pipe. much more so than on a 4stroke. any pipe that's worth paying for is gonna be expensive as sh*t. don't even bother w/ the fmf. it's power curve isn't much better than the stock pipe.
the most beneficial single mod that you can do to a 2stroke engine is the port and polish w/ a good compensating head design. and it's cheaper than a new pipe! huge power gains, but a pipe will be integral to maximize the gains from the p&p.
talk to a good engine builder and you'll get all the info you need. there are 3 or 4 dudes in here that do real good engine work. flotek, wildcard, i think woodward specialties, but i'd highly recommend talking to kennedy_power. he really knows his sh*t and he's got a lot of formal education as well as trail time.
