Generator Hydro Lock Help

[Midnightsun]

The owner of my previous boat is having issues with the generator hydro locking every now and then and would like some suggestions on how to eliminate this issue. Seems to happen mostly when anchored out in rough conditions which I assume forces water into the hull exhaust outlet.

The generator was installed by yours truly when I owned the boat. I used the typical wet muffler setup, a Gensep made by Centek to keep exhaust noise to a minimum. I did install the vented loop/siphon break however I am now questioning this as it may not be working as intended all the time. It did happen to me only on 2 occasions when I owned the boat over a period of several years.

For those not familiar with a Gensep unit, it divides the exhaust into 2. An under water outlet for the water and an above water outlet for the fumes. All you here is a slight his from the exhaust, no more burbling noises typical of almost all marine generators. I call it the sailboat burble.

Generator is a Kohler 5E carbed unit with sound shield installed in the location meant for this on the particular boat in question. In fact there was a tray installed at the factory just waiting for a generator.

What causes water to enter the engine from the exhaust and how does one prevent this? Any and all suggestions more than welcome.

Still have pictures.

[bud37]

Heh there....on the install, I believe there is a required min height above water level ?

[Midnightsun]

QR_BBPOST Heh there....on the install, I believe there is a required min height above water level ?

I should be good since it is installed where it goes from the factory.

[bud37]

Sorry Hans,I am referring to the gen sep itself not the generator.

Viper should be along soon, he will have some ideas.

[Midnightsun]

I did get the gensep up as high as I could with the space that was available.

[Dewmyster]

When I did a similar screwup with my 6.5 I learned quickly to insure the seacock was shut until the Genny started. It is a PIA but if you continue to crank it over the muffler water will back up into the exhaust port.

[tomschauer]

Hans, I assume you have continuous down hill flow from the genny to the muffler?
And the highest outlet of the gensep is lower than the exhaust outlet of the genny?

[Midnightsun]

QR_BBPOST Hans, I assume you have continuous down hill flow from the genny to the muffler?
And the highest outlet of the gensep is lower than the exhaust outlet of the genny?

Yes on both counts.

[tomschauer]

Other than that, I don't think i can be of much help.

[Viper]

All the above considerations are good ones. There's a few things that can contribute to water ingestion, providing it was properly installed, Dewmyster brings up a good point, if she has to crank for a while to start, she can ingest water that's being injected into the exhaust. You said that you installed the Gensep as high as you could but is the height to spec? Is the lift muffler where it's supposed to be? Is the generator running properly and properly tuned and timed? Other possibilities are; running too hot, bad head gasket, bad exhaust manifold. If water is getting in through the hull's exhaust discharge port, a shutter there would help or an inline shutter/check valve close to the genny would work too. Maybe KeithS will have insight on ingestion issues with this particular model.