My old header pipe on my 2000 315 Cota had a massive dent in it so after the dollar gained a bit of ground against the Euro I picked up a new one. I got it in the mail only to discover there is a restrictor plate in the throat of the pipe. Cuts the diamter more than in half, so the area by a factor of at least four. The original pipe didn't have this restrictor or it had been removed by the previous owner. I know this sort of thing can improve torque on a four-stroke but I can't see how it would help on a two-stroke. Does anyone have any information on this???

Edited November 16, 200817 yr by JCBrewer

Bikes as new came with three restrictor plates. The pipe,middle silencer and air box. Just remove.

Used my Dremel tool to cut it out, then ground down the welds. Runs like a champ! Thanks.