I have three questions. 1. Have any of you guys converted from the stock 2001 WR-426 spark arrester to a more free flowing exhaust? If so... What kind of jetting changes were made. 2. I want to change my "YZ" over to the stock "WR" spark arrester and I figure I can make the opposite jetting changes to get close where it needs to be... Right? 3. Does any body have the stock spark arrester form there 2001 WR that they would be willing to trade for the stock 2001 YZ silencer?