With the older FP-series engines that have the iron piston in the steel sleeve, you want to use a fuel with about 20%-22% oil content, with the majority of that being castor oil.

When brand-new, never-run, the engines will need to be run at full throttle and very, very rich..."slobbering rich". It can take 45-60 minutes of this very rich running before the engine will even allow the needle to be leaned. Once it's run-in enough to allow leaning, you can gradually work the needle until the engine will sustain running at full throttle when leaned just rich of peak RPM. The engine is ready to fly when it can run out a tank of fuel (8 ounces for a .35 or .40) without changing the needle setting.

The propeller to use would be a 10 x 6. 14" or 15" propellers are much, too much for that size glow engine. The engine should be running in the 11,000's at full throttle. You can prop it so it's running in the 12's, if your plane will fly with the smaller props ( 9 x 6, 7 or so).