This is a Mega Picco ZX .21 version II mounted on a D8. It was a new engine that is having the same problem since new. It runs perfectly only with a new glow plug (hot MC-59 or OS LS3). Once you run 4 to 5 tanks the engine start to flame out when you open the throttle or backfires and dies when I open the throttle. Put a new glowplug and the engine runs again perfectly. Put the old glowplug on another engine and the other engine runs fine. I am talking here of a new engine with a lot of compression and mechanical pinch. I have worked with nitro engines since 2001 and fixed some "difficult" new engines. I am about to give up on this one.