custom exhaust for KTM-50

haha dude. no such thing. you gotta take a dirt-bike pipe, and cut it at all the welds, reclock it, and weld it back together to fit your bike...adapting a HT exhaust, even a expansion pipe, will hurt performance big time. good luck

ps if you shorten the pipe at all, it will hurt your bottem end, it will shift the powerband up higher. Most people recommend Lengthening the pipe actually, to get more grunt, a cheap way they do this is add more donuts gaskets. I read about some people using like 5-6 gaskets

you can have a two stroke wizzard make you one $$$ or you can go to treatland tv. also check moped army for info on hot rodding. their is a formula on what to build but i can't give change for a dollar. good luck. donuts? umm i like donuts