RE: What is the problem????
Hoss,
For an engine to run/pop, three things must be present in the combustion chamber:
1. Fuel in the mixture
2. Reasonable compression
3. An ignition source
If one of the above is not present; or is, but in insufficent (or too great) amount, nothing will happen.
Too much fuel in the mixture is too rich to fire; and too lean a mixture is just as non-flammable.
A very low ambient temperature may cause low evaporation of the fuel's components (mainly methanol); so too little fuel will be be present in the air, inside the chamber; causing the mixture to be too lean in effect, to be flammable.
But I think this isn't the case.
The settings of the needles have no effect on whether the engine will pop, or not; just on its constant running characteristics.
If the high-speed needle is open enough to allow priming, it will potentially allow the engine to pop and even to run-on for several seconds.
In your case, to me the glow-plug seems to be the culprit.