noobcorpse, where ya been? Haven't heard from you in a while.
TornadoST mentioned a seal kit. In my mind that is extremely
important advice!
Your master cylinder size is on the back side of the casting.
I understand some people changing over to get rid of the 'spongy' brake syndrome, but I've never known the stock calipers to be described as low on stopping power. Mine will make the rear come off the pavement with no problem. I suspect your 'weak braking' is a function of your pads, not the caliper efficiency.
Considering that you have 12k on the bike, have you checked your rear pads lately?
