Hi!
Are you sure the engine gets fuel!??
If there is fuel to the carb the engine cannot refuse to run! Simple fact!
Screw out the high speed needle and blow trough both the fuel nipple on the carb and the fuel intake orifice.Finally check that fuel enters through the nipple by blowing through the pressure line when the tank is filled (so you see fuel entering the carb).

Then use fuel containing 5-10% nitro...more is just waste of money!
Use an OS 8 or Enya 3 glow plug (there are ofcourse many more glow plugs that work too, but those two are "the old stand by's").

Use a 240cc (8oz) tank! No more!!!!
Very important! Always place the tank according to the tank mounting rule, preferable with two clunks (Uni-flow set-up).
Use a 10x6, 11x5 ,11x6 or 12x4 prop depending on model, preferable a RAM or APC prop!

Finally, start the engine at idle and run the engine at full throttle...check the engine setting by holding the nose of the model straight up! Adjust the engine from there!