Switching from one tank to another

[whaler23]

Do you use one tank at a time switching manually via valves to the other tank or do you leave all tanks on and utilize water from both tanks simultaneously? If both are left on what happens if one empties before the other.

 

[REBrueckner]

"If both are left on what happens if one empties before the other."

You lose prime...the pump sucks air.

So better to use one tank at a time....same with fuel.

 

[TopHattandTails]

Just a friendly reminder to check work and understand why a problem is exhibiting it's issues...
I replaced a fuel manifold valve this winter (out of the water). I started the boat up after splash down a few months later and found that instead of 7/8 full tanks each, After a 1 hour run, I had a full aft and 1/4 full fwd tank on shut down inspection. Any way that can happen if your not returning to the same side... I checked my valves on the manifold and I was all correct (each motor drinks from a separate tank and returns to the same tank). So I thought something was wrong with the supply valve I changed (only thing that changed), but a supply valve has nothing to do with a return valve. The levers were in the correct position. completely baffled, I went home for the week and thought some more. Then it dawned on me that the only way this could happen was that one of the return lines was going to the other return tank - impossible in my case, nothing changed and was visually verified. The only other option is that the returns were correct (to the same tank as the motor, but different tanks for each motor), but I wasn't supplying from a tank. UREEKA- both motors were drinking from 1 tank but returning to separate tanks, transferring fuel.... Turns out that some idiot (who shall remain anonymous) installed the new supply valve correctly, but installed the handle basackwards. This would LOOK like all was correct but achieve the transfer I was witnessing. This could have been bad...on several levels.
Lesson learned: understand why the issue is at hand and fix it! Just don't misdiagnose it and move on. And for god's sake- don't install your fuel handles backwards, especially at $5/gallon.
The idiot was appropriately beaten and flogged was was sent to bed with no dinner.

 

[REBrueckner]

Only those who don't do any of their own work have never been initiated into the "dumb ass" (to quote Red Foreman) club. I have been "reinitiated" a number of times. Welcome!

I was running my DD's one winter at my slip when a neighbor knocked: "Your'e pumping fuel out the port overflow!!!" DUH!!!! I,too, was running off one tank and returning fuel to both. For the next ten years of ownership I TRIPLE checked those selectors whenever I touched them.

I have found that when working on neighbors boats, where I am afraid of damaging something, I do better double checking work as I go...and end up with more consistent results.

 

[Canuck Dennis]

Done the same thing as REB, but was coming in to a Marina when it was noticed,
talk about being embarrassed, luckily it was only from anchoring outside to coming inside so not a "major" spill.

 

[bigbill]

same thing here, but i was tied up at my house when it happened. now only a few people on the forum know that i made that mistake

 

[bobk]

I'm waiting for another of our famous listees to own up to a similar issue on the way to a rendezvous. Come on, you know who you are....

Bob