Fuel Selection

Caribe · Apr 8, 2013

Hi: The port fuel tank in my 1979 40 Marine Trader is not drawing fuel properly. ...I have about 200 gals in port and 50 in starboard tank. I shut the valve on the starboard tank to equalize fuel in tanks and both engines gradually started to lose RPM after about 5-8 minutes. I'm thinking maybe the fuel line or vent is partially blocked. Any ideas???

THANK YOU

BTW Just posted a few pictures of our post-restoration. We saved Calypso about a year ago and she has new windows, 4 coats of Awlgrip and 6 coats of varnish and counting... she is a blessing!

Phil Fill · Apr 8, 2013

Undue the gas cap if the problem still exists its not the vent. Many tanks have a valve at the tank to open/close, make sure the valve is open. I draw from only one tank at a time the other two are closed.

When is the last time you changed filters? Do you have primary filters like Raco. If you have Racor you can install a vacuum gauge that screws into the top that will tell you if filters need to be changed.

Caribe · Apr 8, 2013

I did check the valves...The valves on the port tank turn several times lock-to-lock but the valve on starboard tank is different and designed to turn 1/2 turn open/close... I'll check the filters today...a likely culprit indeed!

rwidman · Apr 8, 2013

Yes, a clogged fuel tank vent is a very likely cause of the symptoms you describe.

You can't draw fuel out of the tank unless air can get in to replace it.

Phil Fill · Apr 8, 2013

Caribe said:
I did check the valves...The valves on the port tank turn several times lock-to-lock but the valve on starboard tank is different and designed to turn 1/2 turn open/close... I'll check the filters today...a likely culprit indeed!

It might be the valve is the problem? Might just turn 1/2 turn like the other one does.

Northern Spy · Apr 8, 2013

The stbd tank sounds like it has a ball valve on it. The port tank sounds like it has a gate or globe valve on it. It is possible for the gates or discs to fall off the stem and cause the valve not to open.

Just a thought.

Fuel Selection

Caribe

Veteran Member

Phil Fill

Guru

Caribe

Veteran Member

rwidman

Guru

Phil Fill

Guru

Northern Spy

Guru

Similar threads

Latest posts