I never bother with factory settings. Use an OS #8 plug, Fox R/C, or Enya #4; all work well. An APC 11-4 or 11-5 prop, and 15% nitro fuel. Now when you start it up set it for peak and then about 3 clicks rich of peak, point plane up to be sure it doesn't go lean, if it does then open needle valve with plane pointed up till it peaks then one click rich of that. Now go to idle, set plane down and pinch the fuel line. It should speed up slightly and quit. If it doesn't speed up it was too lean, so open the idle mixture on the right, inside the barrel, 1/8 th of a turn and try again, do this till it it speeds up slightly when you pinch the fuel line. If it speeds up a lot and runs for more than a second or two then it was too rich. In that case close the idle mixture 1/8 th of a turn. After this you should be able to trim out the idle throttle for 2,200 to 2,500 RPM with good transition.

BTW next time you have a stripped out glow plug, have it helicoiled, it usually costs less than a new head.