Holes in the exhaust (on purpose)

[mixelpix]

I've seen a couple different XS's (and other bikes) out there with holes drilled into the back plate of the muffler - gives it a little more grumble(?). Just wondering if this is a significant enough of a modification to warrant rejetting/tuning the carbs? Or is it something which might make the exhaust worse off?

Thanks!

[bandet01]

well i pulled the baffles totally out of my stock pipes and didnt have to mess with the jets but i am getting a 4 into 1 header and i am sure i will have to rejet it for that so i wouldnt think drilling holes would have to make you have to rejet your carbs

[xs650mike]

A common mod in the XS650 and Harley worlds is to use a tapered rod to break the last baffle loose and fold it against the core pipe which increases the rumble factor significantly without necessitating a rejet. Anybody out there done this to their stock XS11 exhaust system?