We have replaced the coil(2X), electronic ignition system, porcelain resistor, carburetor boiled out and adjusted, plugs and wiring...we have had two seasoned heavy equipment mechanics who have tried to solve the issue, and it appears that the engine is getting fuel and spark... If it starts and dies after ten minutes it will not restart under any conditions til the following day...we thought the coil was most likely issue and replaced with new, and when that did not resolve the issue we used a coil we know was working and still the issue is persistent... We also put in a new electric inline fuel pump... So...any ideas we might have overlooked?