My generator has 200 hours total time.  It had been running, underload for about an hour and it shut down.  I am able to restart, but will only run while I hold the start switch down.  New impeller 5 hours ago, and I have good flow out the exhaust.  Oil clean/full, coolant full.  Normally as you start the gen the engine starts, then you can hear what I believe is a relay close...then you can release the start switch and power is available.  It starts fine, but I am not hearing that relay close, so it dies as soon as I release the start switch. 
Any thoughts or experience would be appreciated.
				
			Any thoughts or experience would be appreciated.
 
	