Fuel flow issue

[Joker2]

Just got my new ( rebuilt ) 94' looper 150 have about 4 - 1/2 hrs on it running double oil not exceeding 4000 RPM ( as per mechanic ) I have a 74' v20 with aluminum saddle tanks (20 gal ea.) I ran all new fuel lines with a stainless fuel/water seperator, installed an in line fuel valve on each side ( ball valve style ) My problem is that I can't seem to get the fuel to be taken evenly from each tank. When I open both valves and run it only seems to take fuel from the starboard side tank which has a shorter line because the seperator is on that side. The port side line comes across the stern, into the seperator, then one line out of the seperator to engine. The engine runs fine if I shut the starboard valve and only run off the port. I don't know if it is because of this difference in length or what. Can anyone help ?

[garagenc]

If you are not running a elect fuel pump between the fuel tank and the pump on the motor that may happen. I had another boat that had saddle tanks and the same thing would happen. I finally installed a electric pump and that seemed to fix the problem.

I ran the lines to a "Tee" connection in between the fuel tanks and the new electric pump and then let the elect push the fuel to the motor's fuel pump.

There are pro's on here that may know something else that may help you.

[Destroyer]

As long as the engine runs off of both tanks equally well, what's the problem? I used to run twin tanks with a fuel selector switch. When the one tank ran dry I knew it was time to switch over to the other tank and start thinking about heading home or at least to a fuel dock.. one tank out, one tank in. Worked fine for me and I never got stranded without fuel.

[Joker2]

Yeah I could do that but my problem is the boat lists a lot when one is light and one is full.

[whatknot]

Well, the way I see it, if you don't have trim tabs, you need them. I bought lenco electrics for mine and it was def the best purchase I ever made for the V. Can't believe I ran a year without em!

[Joker2]

Yes, I plan on the trim tabs, what size did you get and how much were they?

[yodaddy]

Originally Posted by Joker2

I don't know if it is because of this difference in length or what. Can anyone help ?

The different lengths and rise on the 2 lines is causing the problem. The fuel pump is sucking from the source of least resistance. You could lengthen the short line to the same length as the long one, and fasten the loop up as high as the highest point the other line runs.

Partially closing the valve on the tank with the short run would also cure it.

Also, make sure both tank vents are open, or if the vents are in the caps that they are working properly.

[Cam]

I had that problem on my 28' Silverton. Listing is a problem. It is the nature of the beast. It will always pull from the closest tank first. How I solved it was to go out on one tank and back on the other. This always kept the tanks around even. Of course you need shut off valves on each tank to do this.

[macojoe]

My V was doing the same, I made the hose the same, vents the same and still nothing!
I did the same mentioned with a shut off on each tank, when one was getting empty I was able to catch it and turn the switch and was always good!
When I converted from I/O I added another 25 gal tank in the motor well, and being I never used more then 25 gal gas just left that filled all the time and the saddle bags empty, boat always level after that

[Joker2]

Thanks guys, I will try wahat you said Yo Daddy