gutting stock exhaust

[cals400ex]

did anyone notice a difference when they drilled holes in their stock exhaust? if so, did you just drill a hole or two or modify the spark arrestor also? i have been thinking about doing this and moving the jet up one size but i wanted to get some opinions first. thanks

[AtvMxRider]

I did it. i could notice a little difference. i drilled an 1 1/8 hole in mine.

[Thumper416ex]

Where did you drill your 1 1/8" hole in the pipe???

[sharpshooter]

I took my spark arrestor out and drilled a 2" hole into the first plate you see in the pipe.I ran it with the spark arrestor.It was the loudest pipe besides TC that I've ever heard.I ran a k&n,165main,dyno jet needle and open air box.It gave me all the gains my fmf does and maybe even a little more low end.

[sharpshooter]

I meant to say I ran it WITHOUT the spark arrestor.