I second the TT Pro recommendations. These are excellent engines. Check your glow plug. Mine runs best on an OS A3 (likes the hot plug). Also better description of what you're doing with the plane when it sputters and dies. Is it idling, half-throttle, full-throttle, transitioning from idle-to-full, or full-to-idle, climbing, diving, looping, rolling, etc. These are key indicators to tell you where to start troubleshooting. My guess is that if it was running well before and starting giving you trouble, change the glow plug. If its happening at full throttle, you're either running way to rich or too lean, if its happening at idle, maybe your idle speed is set one click too low, and if its happening on transition, your low end needle needs adjusting. Also don't rule out fuel delivery problems (are you using a fuel filter? Is it plugged?).

Brad