The catalytic converter is at the base of the muffler can. The problem is that the exhaust pipe is welded to the can. I you can cut off the exhaust pipe, you can likely knock out the catalytic converter and reweld the pipe back on. Or if you have a really long, sharp metal pole, you could poke a hole through the honeycomb and allow gasses to flow freely.
Alternatively, the mufflers for the Honda CBR250R might work. There is some fabrication needed to extend the mid-pipe and to fabricate a mounting bracket (a piece of 1"x3"x.125" aluminum stock works well.) I have an Akrapovic muffler made for the CBR250R and it fits and sounds great.
In terms of power... I don't think that the stock exhaust is very restrictive, but I think the aftermarket exhaust does sound better. I put my bike (with Akrapovic mid-pipe and muffler) on the dyno and my air/fuel ratios was still running a touch rich.
Now... breathing just isn't exhaling, it's inhaling as well. I'm just playing with external stuff (easier on the wallet and my time) but anyone notice anything different here?
