I thought that I had my MT running alright but after reading some of Ray's old posts I wanted to make absolutely sure that the muffler wasn't plugged.
I removed the end baffle and inspected the turbine dealy that others have mentioned. I ground a point onto the end of a wire coat hanger and started poking around in the holes that run around the circumference inside the pipe and after awhile got the wire to go completely through two of the holes and into the main muffler body. The other four refused to open, so I used a long tapered punch and a hammer and forced them open.
Now she:
wheelies
spins out
hits redline in all five
sounds like a genuine two stroke.
My new knobby is showing more use from a 15 minute ride than in all of the miles that I've put on so far this summer.
There is much grinning in Vonda, Saskatchewan.