I have a 08 WR450. Went to remove pea shooter in exhaust today and found its already been removed....Can I take out the spark arrestor aswell? I have a white brothers exhaust (with baffle) but was going to run the stock pipe on it as I like to have a quite pipe... or should i just run the White brothers? The bike needs jetting as it appears to stutter low down.....shall i get it jetted with the stock pipe then put on the white brothers?? Mine is a UK spec bike...I have read about this ASI thing what is it?