Kohler 7.3 Question

[denpooch]

Can anyone give me an idea on where to focus troubleshooting for the following issue?
I start the engine, it turns over, runs for 5 seconds and stalls. Last week I replaced the fuel filter. There is plenty of oil and the impeller is new.
All thoughts and leads are appreciated.

[chpsk8]

First troubleshooting step on a Kohler is to replace the spark plugs. I've never seen another engine that was so sensitive to plugs.
Make sure your power is off also when you start it. Get it running, then introduce the load.

[SplashyLady]

See above - these engines are finicky on plugs, but normally you will drop on cylinder or get a misfire. Your problem sounds like fuel starvation or auto-shutoff:

1. Fuel? How much fuel is in the tank? Remember most boats have the genny pickup above the main pickup so you can't run a tank dry on the genset. If you are 1/4 tank or less, you are sucking air.

2. Oil and coolant level or sensor? Auto shutoff for low oil and low coolant - if both are OK, check the sensors - sometimes the terminals break or a wire comes loose.

3. Fuel filter - how old is it? Have you had any issues with water in fuel?

4. Fuel pump? The electric fuel pumps are pretty reliable, but check connections and output pressure.

Hope this helps - good luck!

[KeithS]

Does it start and then stop when you release the start button or does it continue to run for 5 seconds after you release the start switch. An important difference.
The 5/7.3E series had a bit of a quirky thing with the spark plugs. Due to the design of the Kawasaki intake manifold, the rear plug runs cooler than the front plug. It runs cool enough that at light loads it will foul the plug. An occasional run with a heavy load will help. This does not usually affect starting though. In fact sometimes the generator will run just fine until the load is more than the one cylinder that is firing can handle. Then is will misfire and run like crap.

[denpooch]

Thanks folks.
Full tank fuel. Fuel filter 1 week old. Old filter was changed and it ran well for a while. I thought problem solved. (the old filter was faulty and allowing air to enter the system)
The fluids are topped off but I will check the sensor wires. (I assume I can locate these from the Kohler 7.3 schematic diagram)
When starting, I release and it runs a few seconds and then stalls. I have a Dockmate who has an issue where it will run until he releases the switch and then dies.
One guy said it may not be putting out enough voltage and it can be a voltage regulator issue.
I appreciate your help.

[buster53]

My problem was the anti-siphon valve in the gas line. Replaced it and all was good.

[KeithS]

The reason I asked about the 5 seconds is that the controller ignores the engine shutdown sensors for the first 5 seconds of operation. Check the obvious that the oil level is full. If it is disconnect the oil pressure, exhaust temp and engine temp sensors one at a time and see if that is your issue.

[denpooch]

Thanks folks

[denpooch]

Update: I changed the fuel pump and all gas lines to the tank. Additionally, I replaced the fuel filter again.
She was running GREAT, until....
It was running fine the other day and then started 'searching' (ie.rpm's increasing-decreasing, etc). Eventually it stalled.
Now I start it, it searches for a few minute and stalls.
Question, is there an adjustment on the carburetor to overcome that issue or is it best to replace the carb which is only about 2 years old.
If an adjustment, can you let me know where I can find the adjustment screw?
Thanks.

[Gary Rose]

I have the same problem , mine was overheating. When it overheats it shuts down the fuel pump. I have replaced everything. Stat waterpump cooling chamber head gaskets , impeller, have burbed system several times. Still running hotter them usual and shuts off at times. Cant figure out why, looked to replace but Kolar does not make a gas genny anymore. Owens is about $12.5 good luck and let me know what you find.