I found an easy and fast way to straighten a bent FMF Power Core 4 (non-spark arrestor). I happened to have a 7 foot section of 1 1/4 inch square metal tubing laying around the garage. First i used it to straighten the sub frame. Then i noticed that it slips perfectly into the square bore of the silentcer. With 1 or 2 small tugs i straightened a fairly tweeked silentcer. It sounds like caveman engineering but it was fast and didn't hurt the inside fo the pipe!