Holes on the exhaust???

[Juanfer]

[pantablo]

there's a description of this mod on Joris's site: http://www.bikepower.net
including a sound clip I think.

Doing this adds sound and doesn't hurt or help performance.

[rprata]

I did this mod to my '96 GS not too long ago, and i must say it does sound better than the stock exhaust, and I don't notice any power difference (better, or worse).  If you want to make it sound a bit better, do it, but BE CAREFUL or else you'll be buying an F1 slip-on to replace your broken stock exhaust.

Mod took me around 5 min. with a good power drill.