Use a caliper man measure the low needle depth. It should be .020deep to start. I suspect that you may have blockage inside the carb. When you prime the engine (Block the exhaust and start engine with out igniting glow plug) dose fuel spray out the carb when the air filter removed? It should...
Are you using a fuel filter? Sounds like the carb is blocked and starving fuel. The stock setting are flush inside ring on low and 4-1/2 turns high. Is where I always start. I use fuel with 18% oil lube to. less is best