Hey i was curious if any of you guys have modifed the stock pipe on your yfz. How were the power gains. I plan on gutting my pipe so it will almost be a straight pipe. and im hooping that with a kan and jetting will help with power what do you think.

 

I think the only thing you should do is remove the "p-shooter". Other wise you have a good chance of loosing all your bottom mid range, and maybe gaining some topend. Not to mention that its going to sound like BUTT!

 

I already removed the pee shooter. do you know wher i can get a uneversial spark aresster that will fit in the big opening. i cant find one. thanx any help would be welcome as i plan on doing this soon.

 

I think the exhaust is still considered to have a spark arrestor in it, as it is not a straight through pipe. there is a big wall, or cap shoved way down in there. That is going to stop any spark that comes out of the back of that thing in a real hurry!
I think the p-shooter is nothing but an emissions control devise, a power robber, and a sound limiter. I dont believe it has anything to do with a spark arrestor, as like I said, any spark that come down that pipe is going to be immediatly stopped at that wall half way down the muffler!
IF you want to do anything further to that exhuast, I highly recomend you NOT, and you just go buy yourself a slip on. There only a few hundered dollars!