Genset running out of fuel

[bud37]

Does the generator act the same way when the main engines are off ?

If so shut off the fuel to engines valving ( isolate the mains ) while running the gen and see if the same thing occurs.

[MyPleasure]

Hi Bud37. I haven’t run the mains for long enough to see if I the generator quits while they are running. I have for a short time, like maybe 3-4 minutes to see if it will help draw fuel to the generator, but that didn’t seem to make a difference.
I know that the generator fuel pump is working properly, it just seems to run out of fuel after 10-20 minutes. Like I said earlier, I’ll check the current valve to make sure that there is no leak, and if that doesn’t seem to be working properly, I’ll install a new switch.

[bud37]

Imo...the mains will not help to pull fuel for the gen, they will compete with it for supply depending on how you have the valves configured. Consider vapor lock from increase in suction pressure if all mechanical fittings end up being in top shape, lets see first though with the valve check.

Good idea checking for air infiltration. It is still good practice to have the gen on its own fuel supply lines from its own tank pickups though.....good luck hopefully it is something real simple.....

[km1125]

Not sure I'd like that additional "complication" of having the genset T'd into the main engine fuel lines.

[MyPleasure]

Not much that I can do about the fuel line, as far as I can tell, it came this way from the factory. If the generator was added aftermarket, I could see them installing the fuel lines this way rather than having to remove the fuel tanks to install a separate fuel supply for the generator.There is definitely no room to install a separate fuel tank for the generator.
I never checked how the generator on our 4207 got its fuel, but I know that it did draw its fuel from the port tank. Being diesel, it was great to have the fuel transfer pump to help level the boat out after using the generator. But I never had much for solar power back then, so the generator was used a lot more.
I would like to hear from other owners of this model with gas engines to hear how their generator fuel lines are installed? I think this model is a 1992 3608, I believe that they were built from 1990 - 1995, then they extended the swim platform and called it a 405 - 406.

[ColRon]

Are you sure it’s a fuel problem? I say this because last year my gas genny would run about half an hour or so and then shut down. I thought I was having a fuel issues, because after it sat a while (20 min or so) it would fire back without a problem. I finally figured out that it was over heating. And while the impeller had been replaced and it was pumping water, it wasn’t pumping enough due to a blockage from bits of previous impellers. After a good cleaning and flushing of the raw water cooling, it no longer overheating and my shutdown issue has disappeared.

[KyleR]

I finally figured out that it was over heating. And while the impeller had been replaced and it was pumping water, it wasn’t pumping enough due to a blockage from bits of previous impellers.

Similar thing happened with ours - but it turned out that the intake strainer (the exterior one on the hull) had been painted over multiple times and was clogged. Luckily I figured it out and was able to thoroughly clean it out during a short-haulout to swap props. Ran perfectly after that.

Good luck and please keep us posted when you find your solution!

[MyPleasure]

Thanks fellas. There is definitely no problem with the cooling, I put a full port ball valve just above the thru hull, and it pumps an amazing amount of water! Funny though, none of my previous Carvers, also our present one, never had strainers over the intakes for the generators. I just installed one on this boat this year. On our Uniflite, when we were running the generator one time, I noticed a difference in the exhaust sound, shut down the generator, and found 2 small fish stuck in the intake.
It’s definitely a fuel problem, the fuel pump is dry after it stalls. It’s like there’s a fitting not tight, and the fuel pump looses its vacuum, and the fuel pump is not pulling fuel. I took the fuel system supplying the generator completely apart and found no fuel restrictions of any kind, and the tank selector valve is in perfect working order. I actually bought a new switch valve, and found that the ports were not properly aligned, which wouldn’t allow a full amount of fuel from the factory, unlike the original one,
I am wondering if the 1/4” selector valve currently installed for the generator is big enough, but it’s only a 3 cylinder Westerbeke, so it shouldn’t burn a lot of fuel anyway.
Anyway, another project for after the weekend.

[g36]

Why not try a temporary external tank as I suggested earlier to eliminate any issues with valves or fuel starvation concerns?

[Viper]

I agree