Glad you liked the Yamadog crack
  I am a two stroke guy from way back and threw a bunch of A-1R parts on my A-1SS Kawa. Ungodly acceleration for a 250, but ate piston rings like crazy. 
 As for sources, there are probably a few for TZ's and similar boy racers

 I have got things for people in a lot of different fields like trails, older Kawas, etc. If you know of a source or need to find something, maybe I can help. 
 Need to make a decision on the ST4 by this weekend.....hmmmmm