1) Richen the idle mixture a LOT! Open high-speed needle about 2 turns out from closed.

2) Start the engine at 1/3-1/2 throttle.

3) Leave the glow plug battery connected and advance throttle to full.

4) Lean the high-speed mixture to just rich of peak RPM.

5) If the engine will sustain running there, then you can retard the throttle and adjust the idle mixture. You will likely have to start leaning it at about 1/2-3/4 throttle as it richens when it enters the midrange.

If your engine won't take a set, then it's likely that something's wrong, such as a bad piston/liner fit that causes compression loss when the engine warms up.