Does anyone know if the FMF powerbomb will fit the stock 2008 YZF shorty muffler? I am interested because..... ....I had decided that I was going to purchase at least a slip on exhaust for my bike to get back all the power that it lost to the cone baffles in the shorty exhaust. Before making a purchase I decided to experiment.....Armed with my Makita drill and Blue Point 3/8" pencil die grinder I completely disassembled the muffler. Using the die grinder I cut out the cone that mounts at the exit "mouth" of the exhaust since it was the most restrictive. I left in the middle baffle since it is completely perforated from the factory and not "too" restrictive. The muffler was assembled with fresh packing and new rivets. After adjusting the carb slightly according the EGA machine I tested the scoot that night. Much to my surprise (I had great doubt about any positive gains) the powerband now was stronger from the bottom to the top. The bike now revs quicker and faster and feels very much like...dare I say 2-stroke? Also the sound is very similar to stock pipe I had on my 2007 YZ450. Again I want more power but want to keep my muffler so I am looking into the FMF powerbomb. Thanks. So inconclusion: gutting the restrictive short muffler works and provides favorable powergains if you like that style of power.