6-29-02 MY fault, NO problem with the Powermaster fuel. Yes i had trouble with my engines overheating, I spent half a day trying different things nothing would work, then it hit me, I was looking in an empty engine box and noticed some extra head gaskets, these are to lower the compression so a higher nitro fuel can be used. I ran to the local hobby shop and bought the coldest glow plugs they had,( OS R5 ) This fixed the over heating problem instantly. Didnt even have to add the shims to lower compression. Pleanty of power , can almost grab the muffler. after shutting engine down. I have been in modeling for 37 years, I guess I just wasnt thinking,I know better. Must have been a ( senior moment )