Dirtbiker05 Posted July 26, 2006 im looking to quiet down my 02 yz250f, it has a fmf powercore iv. can u put exhaust packing in this exhaust system? thanks in advance. Share this post Link to post Share on other sites
burgunder Posted July 26, 2006 Most if not all exuasts systems have some sort of packing. Yours certainly does. The packing will obsorb sound waves keeping the bike quiet. Overtime, the packing gets cloged with carbon from the exaust gases, so you need to replace it. Just remove the end of your muffler and slide the inner pipe "has holes in it" out. Remove the old packing. It should look like fiberglass house insulation. Replace it with new packing. Some of the 4 strokes have a steel wool looking mesh between the pipe and the insulation. You should replace that also. If your packing is very old, the new stuff should quiet your bike down some, but don't expect that much. If you need more suppression, you can get end caps that also reduce the noise. Just do a search (if it is working). Share this post Link to post Share on other sites
Dirtbiker05 Posted July 26, 2006 thanks. will i lose much power if i do replace it? Share this post Link to post Share on other sites
burgunder Posted July 26, 2006 If you replace the packing, you will not lose any power. Share this post Link to post Share on other sites
Dirtbiker05 Posted July 26, 2006 so theres no way to make the bike more quiet then it already is? Share this post Link to post Share on other sites
Slodad Posted July 27, 2006 Most manufacturers sell smaller diameter inserts or end caps that reduce the sound. They tend to also reduce the low end power. Top end power seems not to be affected so much. Share this post Link to post Share on other sites