Replace the glow plug, run-in is rich and can burn plugs out fast, it also sounds like you tuned it to early sending it lean, bad idea, leave it factory set for a few tanks and run it in, a lean run-in will make tuning and idleing a butache forever.Set it back to factory and put up with the stalls from being rich, run it in then tuned for speed.Always clean air filter after every run when running in.