I need a spark arrester to ride OHV parks. I have an '04 CRF with an 88 kit and a Powercore 4 big bore pipe. Does anybody know if FMF has replacement spark arrester end caps that would switch out? Is there some sort of aftermarket add ons that fit. Anyways, I posted a want ad for a stock pipe with the spark arrester in tact so I could just switch it over for the trails. Also, I'm pretty sure it won't fit, but does anybody know if a Yamaha TTR pipe will fit on a CRF? I have one in storage, so I though I would ask before I try, but I am doubtful they fit.