I have a 2005: Kohler 5E generator on my 2005 PC 27. Surprisingly low number of hours on the generator, approximately 30. The generator consistently runs for about an hour and then shuts off. Is there any way I can see codes to diagnose the issue? Or any suggestions? I did replace the impeller, new plugs, basically tuned up the unit last year. Strainer is empty as well.
Happy to assist you if you are still having issues. I have service manuals and can share them with you if you like. This unit has a number of LEDs on the circuit board - when the unit shuts down it will illuminate one of the LEDs - which one illuminates will help you identify the problem. However based on your information, the unit is likely shutting down due to a safety trigger - low oil pressure, high engine temperature, or loss of coolant.
Any one of those could be your problem and will need to be diagnosed individually. The coolant one is easy - just look to see if you have coolant. The other two you'll need secondary gauges to confirm the temperature and pressure are within specification. If all of those are good you then need to check to see if any of the actual sensors are faulty.
If your getting high temperature shutdown and there is still water streaming out of the side you could have an issue with the water pump on the engine itself (not the seawater pump). My guess, if its not a bad sensor, is that your issue is that coolant is not being moved through the heat exchanger and generator. This could be a thermostat issue on the engine or water pump issue.
Lastly, and very unlikely, there could be an issue with your voltage regulator. The voltage regulator supplies current to create a field within the generator. If this stops providing the voltage the generator will stop producing electricity and the there will be nothing to ignite the spark plug on the engine (instead of the engine having an alternator it just uses the generator). However these generally either work or don't work - not an intermittent thing.
To me it really sounds like a temperature issue. Your getting conductive cooling from the seawater moving through the heat exchanger, but maybe the coolant isn't being circulated through the engine so eventually it overheats. After some amount of time the coolant will cool down and the generator will be able to be restarted. When you get a shutdown look at the circuit board and see if LED 4 stays illuminated. If so you have a problem on the safety switch side - start with temperature sensor.
