Read the part in your manual about carburator needle settings. It sounds like you high speed
needle may be set too rich (too open). First take glow plug out of engine. Flip car over and let any excess nitro drain out of engine. Flip car back over, Inspect glowplug (coil should be tight and straight, not bent or knotted) Replace glowplug, Then turn the highspeed needle 1/4 turn clockwise
. Make sure you glowplug charger is fully charged. (You can test it on glowplug before you relpace it in engine). Check that all fuel and exhaust lines are secure. Place glowcharge on glowplug procees to start engine with pullstart/rotostart. If need be, prime the fuel ine once or twice but don't flood engine.
Hope this helps......if not go check out these articals for furhter assistance.
The Break in Bible
and The Tuning Bible