Hey all. Im new to this forum and am still learning my way around. I have a 1986 Fourtrax 250 that i aquired a little over a year ago. I tore the engine down about 6 month ago and wound up only honing it and replacing rings because it was in such good shape on the bottom half of the topend. On the cyl head, well i just cant leave well enough alone. I work in a machine shop in the racing engine business. To make a long story short i had the head on the flow bench and done a valvejob and some port work. I wound up gaining 20 CFM on Int and 14 on Exh. Theres a little overview of wear im at with it. Now i have a couple of questions about some parts. Im looking at the Cobra Megaphone exhaust mainly because i have 13.50 Super Swampers on the rear and they rub the stock muffler, and the cobra system looks smaller. Are they any good? Another piece i run across was the ricks motorsports hot shot CDI box. Says it has advanced ign curves and raises the rev limiter. Is there anything to this CDI box?. Sorry this was so long. Thanx for any input.