Kohler 6.5 on 1994 390CPMY shuts doen

[tonyiiiafl]

Her is a stumper for me. My Genset has always been very reliable. However, today, it shut down suddenly. It restarted after a few moments, and ran for a short time, and shut again. Surges when first starting and then smooths out. I checked fuses, and also connections. Plenty of water flow out the exhaust. I tried a spray of gas from a spray bottle to restart but crank and then no start. I have replaced the capacitor last year, and again, no issues. Changed the gas filter. I use a Quick Silver 35-802893Q01, so plenty of capacity. Voltage at 120. It just cuts out and dies.

I had marina replace the anti siphon fitting over the winter just because it was 26 years old. Happened whether on aft tank or main, although I believe it only draws off of port tank. nines run fine. It just died after 6 minutes of run, and restarted like nothing happened. Any ideas???

[tonyiiiafl]

Also, after the first episode this afternoon, I removed the air filter and it fired right up and ran for 2.5 hours until I shut it off. Just another thing to think about.

[tonyiiiafl]

Well, her is a ditty... I went down into the bilge and replaced the old air filter. Crank but no start. I removed the hose that send filtered air to the carb and she fired right up but would only crank with everything connected. Once running, I connected the air intake hose to the housing and it surged for a few seconds and then kept on running. There is a second hose, smaller, that goes from the air filter housing to the carb. In between is a valve, so to speak. Is that a barometric type valve? I think I am getting somewhere here, but need opinions.

[Viper]

The actual model number would help but if it's the one I'm thinking about, there is a fuel filter (secondary) in the unit right at the fuel pump. It'll look like a large fitting but it's a filter. If your primary filters have let debris through over the years, and the secondary is still original, you should replace it. It may not solve the current problem but it's something you need to eliminate as a possible culprit. The filter I'm talking about looks like this, if it's still original on your unit, it may be painted white....
https://apelectric.com/kohler-267987-fuel-filter

[Viper]

Tony, again if it's the model I'm thinking about, the spark plug cap assemblies at the end of the plug wires are actually noise suppressors and are notorious for corroding after a while and causing intermittent ignition problems.

[tonyiiiafl]

The model plate is missing sadly it is all I have to go on is a 6.5 from the build sheet. I am going to check for that secondary filter. I checked thug caps and all looked fine. I will send a couple of photos when we get back to the slip. Thanks again.

[tonyiiiafl]

Here is a. Photo of the 5KW model, which looks exactly like mine. I have noted the secondary hose from the filter box to the carb. Then in a yellow circle is the Pressure(?) regulator vale I am speaking of. That secondary hose goes into it before it changes to brass/steel/copper line and a ferrule fitting into the carb. [image https://www.ebay.com/itm/Kohler-5E-5-kW ... SwI49eZaYH][/image].

D665A776-9EAE-4D10-83D8-A065AE6F0646.jpeg

[bud37]

Have you checked the choke operation on start up ? It should open the choke plate wide.

[Viper]

One line should be the fuel delivery line and yours may have a fuel recovery line. Both should be metal lines. I believe there is a vent and vacuum hose at the breather but I don't recall any special valve there, might just be a fitting.

Bud brings up a good point, make sure the choke is working properly. I think it's solenoid activated.

[tonyiiiafl]

Choke plate appears to be functioning properly. When I start from cold it will shut for 3 or 4 seconds, open and close again until it fires off. SO it that is a fuel recovery line, I would assume the excess or recovered gas will go back to the air cleaner to be burnt again?