Vacuum Gauge PSI advise.

[Mellieha]

Hi Sailorchic34 and DeepFrz,

There's a third filter and this small filter is on the engin itself. So from the Racor2microns to --->3rd small filter on the engin to ----> Fuel pump injector.
I'm getting air in the lines and I'm wondering if it's a mistake to put this 2microns there ? It causes high suction for the lines? so air can sneak in ?


Thks

[sailorchic34]

Originally Posted by Mellieha

Hi Sailorchic34 and DeepFrz,

There's a third filter and this small filter is on the engin itself. So from the Racor2microns to --->3rd small filter on the engin to ----> Fuel pump injector.
I'm getting air in the lines and I'm wondering if it's a mistake to put this 2microns there ? It causes high suction for the lines? so air can sneak in ?


Thks

Yes, three filters can cause rather high pressure drops. What you could do is abandon the third filter and connect the far better 2 micron filter outlet to the injector pump. IF I recall correctly (always questionable) yanmar engine filters are ~10 micron anyway.

[DeepFrz]

Actually I would put the pump between the 2 micron filter and the on engine filter. Have you changed the on engine filter recently?

Air leaks are usually a result of a problem connection in the fuel line or faulty O ring on the Racor filter housing. Also could be a pinhole leak in the fuel pickup tube inside the fuel tank. The Racor filters have a large O ring near the outside of the top piece and another on the T handle. These both need to be checked and replaced if necessary. Another source of air leak is the bottom drain assembly on the Racors.

Edit: the on engine filter is a pressure filter and meant to be downstream of the pump.

[Mellieha]

Thanks Sailorchic34 and DeepFrz,


These 2 Racors 10 and 2 microns are newly installed last year. I did average 40hrs of engin use each year on lake Ontario.


I will check the O ring and lines connections and the bottom drain assembly.

To pinpoint the air leak. I'm thinking to use a soft cloth with soap and just turn on the switch for the electric fuel pump only without cranking up the engin, and run the rag with soap on every connection. Do you guys think it would work?

Thks

[sailorchic34]

Originally Posted by Mellieha

Thanks Sailorchic34 and DeepFrz,


These 2 Racors 10 and 2 microns are newly installed last year. I did average 40hrs of engin use each year on lake Ontario.


I will check the O ring and lines connections and the bottom drain assembly.

To pinpoint the air leak. I'm thinking to use a soft cloth with soap and just turn on the switch for the electric fuel pump only without cranking up the engin, and run the rag with soap on every connection. Do you guys think it would work?

Thks

I wipe the hoses / fittings after an engine run with a clean paper towel and look for fuel. Any fuel found indicates a leak.