I work for Z's R/C Hobbies and we carry the powermaster GMA blends 5/22 and 10/22. My question is, I have a OS BGX-1 w/ Bisson pitts muffler and a perry pump (VP-30) and the fuel I'm using currently is a 10% nitro 18% oil (S&W) and the motor does not run very cool (around 220f - 260f without cowl) or good at all. I have tuned, tuned and tuned again with the same results. So now I believe to be the fuel. Would it benifit me to run the 5/22 or 10/22?

The fuel brand is not necessarily the problem. I have yet to see a BGX run well unless it had on-board glow that is on most of the time. If you are going to try the PM fuel, try the 5%. Last BGX I had did'nt like much more than 5% fuel from the best I can remember. Don't blame S&W for a bad running BGX. Thats like blaming Mobil fuel for a bad running AMC Gremlin or Pacer.
220 to 260 is not hot at all, in fact that is a bit on the cool side.

Thank You Fuelman, I'm planning on putting an on-board glow system and I will try the 5/22 PM fuel. Thanks again.