[jclark003]

Not a Kohler expert but you typically need to determine of it is a mechanical issue (engine overheating, fuel starvation, etc) or a control issue (bad relay, control board, etc). For starters would wait for a shutdown then check the state of the sensors (coolant temp, oil p, exhaust temp, etc) to see if one of those are tripping a shutdown sequence. otherwise as Capt Brett indicated you can get real deep trying to troubleshoot control issues and or intermittent problems like an electric fuel pump going bad. A service manual and DVM are pretty important for troubleshooting. If you turn to a professional make sure you find someone who has experience with generator controls.