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Fuel Line: one tank always stay full.

kendrew

New member
Good day Chrysler Crew.

I have two gas tanks on my Uniflite 23 boat. I did all the tracing and pictures see link.

https://photos.app.goo.gl/7bLkPvT7UukMUpNP9

The Starboard Tank goes down and the port tank remains full. I did not see any shutoff valve unless is well hidden and cannot access it.

I will do more probing but was wondering if you see something wrong from the pics and marking provided.

Cheers
Bob
 
I would put in a 3 way valve there. You run the risk of sucking air since air is easier to pull than fuel.
 
Bob,

I had a similar problem. How old are the fuel lines? They could gum-up internally and reduce, if not block, fuel flow. Also, your fuel tank vent could be fouled with bugs, dirt, you name it.

I suggest to test, that you use compressed air and carefully back-blow your fuel lines to clear any obstructions. Pay attention to differences between port and starboard. I think you will likely find that replacement of all fuel lines is in order.

Tip if you do replace. With old line disconnected, tape a double barbed fitting to splice old line and new. Then use old line to pull new one along in the same locations and path as old. Of course your fastening points will need to be removed first.

Good luck, Noel.
 
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I suggest to test, that you use compressed air and carefully back-blow your fuel lines to clear any obstructions. Pay attention to differences between port and starboard. I think you will likely find that replacement of all fuel lines is in order.

Unless there are anti-siphon valves on the tanks, then don't do this. ;)
 
Each fuel tank's outlet should be equipped with an Anti-Siphon valve.
The Anti-Siphon valve is nothing more than a one-way/spring-loaded/ball-check-valve with a light spring value.
They allow fuel to flow under fuel pump suction, but will NOT allow gravity fuel flow (USCG regulation).
Fuel pump suction can easily over-come the ball-check's spring value.
Not all Anti-Siphon valves "check" with the same value.

With dual tanks (that each feed both engines), it may be possible that one Anti-Siphon valve is creating more resistance than the other, hence the idea of the Port side tank not being able to feed as much fuel to the engines!

Also, remove the fuel tank pick up tubes and look for any debris on the screens that may be restricting fuel flow.
Clean and reinstall.


Suggestions:

Safely and temporarily install vacuum gauges down stream of the each Anti-Siphon valve. See if each gauge shows the same vacuum value.
Swap Anti-Siphon valves and see if the issue follows the Anti-Siphon valve. If so, then there is your problem.
Replace both Anti-Siphon valves with new.




.
 
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