Hi Gang, Windy flying today in eastern Pa, but my plane came home intact. I am new to 4 strokes, just mounted an old OS 90 in my Global 60 hi wing. The fuel inlet on the engine is about 1 1/4" above the tank outlet so I put on an 8-32 pressure fitting on the muffler. The engine came with a screw in the hole in the muffler, have no idea why. Was this engine designed to use pressure to the fuel tank? I used 15% 2 stroke fuel, all I had and tried both a 12-10 and a 13-6, both worked but the 13-6 seemed better. I suspect I should go to maybe a 13-8?? I was getting quite a bit of smoke at idle and acceleration but not much in the air, normal? I used an OS type "F" glow plug. I found the hi end needle to be quite sensitive, not much adjustment needed to make big changes. I ran the engine and pulled off the pressure line, put my finger over the fitting, and was amazed at the amount of pressure created! Really quite a lot. I have no instructions for the engine, so if anyone can give me some pointers it would be greatly appreciated! BTW the guy who gave me the engine hadn't run it in quite some time, stiff and gummy, but I bench ran it to loosen it up. After about 5 flights I noticed the compression was considerably less than at the beginning. But, maybe I am used to hi compression 2 strokers! Should I be using 4 cycle fuel or do you guys use 2 cycle fuel? what about nitro content? Apologize for such a long post, but I am confused. Thank you all for any tips! Bill O'Neill Queen City RC Allentown, Pa.