Hi. My Mach .26 has suddenly "died". The engine starts when cold but stalls after a minute or 2 minutes and will not start again until ice cold again. Have changed glow plug, opened it up and checked for scratches on the sleeve and piston but cannot see any with the eye. The front bearing seems fine with the naked eye. I also sealed everything that I could i.e. carb and backplate but to no avail. Could dirt have caused very very small scratches that result in compression lost and subsequent stalls?? Any ideas or suggestions that I can try to confirm where the problem resides?