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Kohler gas generator question

outobie

Regular Contributor
is there a forum section to get help with a gas generator?

looking for thoughts and suggestions on a generator issue I’m having

a boat I recently bought has a kohler 6KW gas generator that starts easily and runs perfectly for about 35 minutes. Then it begins surging reving up and down for about a minute then dies. It won’t restart at all . It spins but doesn’t fire. After you wait for an hour it fires up again and will go through the same process again.

the boat is a 2006 searay 340. Engines are 8.1 mercruiser horizon V drives with 750 hours and run perfectly. The generator and starboard engine feed off of the starboard fuel tank which has all new fresh fuel. Generator was not used by original owner much and only had 30 hours. A new carburetor and new fuel filters have been installed. The generator did the same thing with the old carb and old gas as it does with the new carb and new fuel

my thoughts fir what what to do next are
new fuel lines and new fuel pump.

it seems like a fuel problem to me. Thoughts or suggestions are appreciated

thanks
 
I'm thinking fuel supply....separate anti-syphon valve at fuel tank? everything 'tight' on the suction side?

Anything in the old filter?

think best would be to install vacuum gauge on suction side of fuel pump and observe what happens until the generator dies.....
 
fuel supply was my thought as well. the old filter was dirty as can be but now it's got a 2nd new filter and a new carb and is doing the same as with the first new filter and old carb that was cleaned out.

there is no separate anti-syphon valve on the shared fuel tank. there is an emergency fuel cut off solenoid which I'm not sure how to test...does seem to have a bypass mode though which I'll also try this weekend.

I need to get new fuel lines made. these have crimped on fittings on the ends. they look perfect and feel good but are 12 years old and due for a change. I haven't figured out what kind of fuel pump I'm dealing with yet but assume it's electric.

I've also read of another person with same boat and generator with a similar problem. turned out to be an overheating issue that was causing the shutdown so will look into that as well and service the impeller and antifreeze, which are also past due to be changed
 
Well it doesn’t seem to be an overheat issue. Installed new impeller, and capped off and burped the antifreeze which was a tad low. Added New fuel filters again. Dumped the gas into a jar to inspect and it looked perfect.

i forgot to order a new fuel pump so that’s next on the list. For good measure I also replaced the spark plugs. The old ones were not terrible but not great either. At the moment it will not start. It cranks great and will catch and start to run for about 5 seconds then stall.

It has great spark so now I’m back to fuel. I also confirmed the fuel pump is getting electrical power. The voltage seemed vary between 10 to 12 volts but since i was only able to test while cranking and not running it may be throwing off my readings.

i did not have any vacuum gauges available to test fuel pressure.
 
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