Reviewing this thread, I would like to hear what exactly happens if the NV is opened "more". Does the engine quit, or does the NV fall out of the spraybar?
If the engine quits, it could be the glowplug. If the NV falls out, then it's a kinked fuel hose or clogged filter (which is more likely if the filter is installed backwards to the flow direction).
The reason I ask is because we had a young fellow who was gifted a thoroughly worn Fox .35 Stunt (not by me...I'm not that mean). The glowplug was burned out, and he relied on the LHS to select the correct glowplug for him to purchase. They sold him a "short" glowplug of some sort. The engine would run, but the NV setting was on/off, with no range. I screwed in a Thunderbolt LONG idle bar and all was well. Free, I might add.
Steve