Sounds Like an air leak.
Did you check your fuel line?
Did you check your pressure line from exhaust to fuel tank?
Bad Oring inside fuel tank lid?
Check exhaust gasket where header mounts to engine.
Check exhaust coupler from header to pipe.
Is Glowplug tight?
Are Head bolts tight?
Did you seal the engine with silicone sealer?
Orings on high and low speed needles could be torn!