Vacuum Gauge PSI advise.

[Mellieha]

Newbie here, Looking for advise from experts.

I have a Yanmar YSB12 and I i'm looking for a vacuum gauge to keep an eye on the engin when air gets in the line and or when the fuel filter gets clogged. Can someone tell me what size of PSI do i need for this engin?

Thanks alot

[sailorchic34]

Vacuum gauges are in inches of mercury, 0-30" though 0-20" would be fine for the yanmar. 8-10" would be too much vacuum, BTW and would mean the filters were clogged

[HappyMdRSailor]

Originally Posted by sailorchic34

Vacuum gauges are in inches of mercury, 0-30" though 0-20" would be fine for the yanmar. 8-10" would be too much vacuum, BTW and would mean the filters were clogged

All my vacuum gauges are calibrated in "fingers of whiskey"....

[a64pilot]

Originally Posted by HappyMdRSailor

All my vacuum gauges are calibrated in "fingers of whiskey"....

I've got a "whiskey compass" does that count?

[Mellieha]

Thx Sailorchic34,

Where should i install the new vacuum gauge? here is my lines and fuel filters:

Dieseltank(in the bilge below the engin) to--->(1rst filter)racor10microns to---- >AirtexElectric pump to--- >(second filter)Racor2microns ----> to the enginYSB12.

Thank you

[sailorchic34]

Originally Posted by Mellieha

Thx Sailorchic34,

Where should i install the new vacuum gauge? here is my lines and fuel filters:

Dieseltank(in the bilge below the engin) to--->(1rst filter)racor10microns to---- >AirtexElectric pump to--- >(second filter)Racor2microns ----> to the enginYSB12.

Thank you

Between the racor and electric fuel pump will do.

[HappyMdRSailor]

Originally Posted by a64pilot

I've got a "whiskey compass" does that count?

Oh man... You maka-me google again!

But filling the binnacle with consumable alcohol... That's a GREAT idea!

Originally Posted by Mellieha

Thx Sailorchic34,

Where should i install the new vacuum gauge? here is my lines and fuel filters:

Dieseltank(in the bilge below the engin) to--->(1rst filter)racor10microns to---- >AirtexElectric pump to--- >(second filter)Racor2microns ----> to the enginYSB12.

Thank you

One gauge? Between the 10 and the 2, before the pump.... That way you know when your 10 is gettin' icky...

[model 10]

Originally Posted by HappyMdRSailor

One gauge? Between the 10 and the 2, before the pump.... That way you know when your 10 is gettin' icky...

Finally I get some numbers, thanks. Mine stays at about 2" but I did not know how low it might go. I think some of the vac gages just have an green arc and no numbers.

[Capt.Don]

I'm a little confused by this - I added a Racor vacuum gauge on the outlet side of the primary Racor filter. The gauge consistently reads '0'. I've talked to a few diesel mechanics and they indicate that this is good and will only increase when there's reduced flow on the filter. As a point of reference, my primary filter looks as good as new, there's never been any sediment or water.

Don

[goboatingnow]

Originally Posted by sailorchic34

Vacuum gauges are in inches of mercury, 0-30" though 0-20" would be fine for the yanmar. 8-10" would be too much vacuum, BTW and would mean the filters were clogged

Racors T handle gauges are marked in Hg and Kpa and have a convenient yellow and red markings to show when problems are starting


Dave


Sent from my iPad using Tapatalk

[sailorchic34]

Originally Posted by goboatingnow

Racors T handle gauges are marked in Hg and Kpa and have a convenient yellow and red markings to show when problems are starting

Quite correct. However racor whats $96 ish or more for the colored vacuum gauge and tapped T handle that can be had for $12 at granger (though without the yellow and red graphics) and maybe another $2-$3 for a hose tee. On the racor gauge, yellow starts at 6" and red starts at 10 inch.

Generally changing filters at anything over 5" is a good idea. A new filter should read 0 on a smaller sailboat <40'.

[DeepFrz]

Make sure the vacuum gauge you get has a tattle tale needle. This is a needle that will stay at the highest reading even when the engine is shut down. You have to manually reset it.

Your pump should be downstream of both filters and IMO your vacuum gauge should be between the 2 micron and the pump. Racor filters (I presume the 500 filter/vortex separator filters) are made to be upstream of the fuel pump.

[sailorchic34]

Originally Posted by DeepFrz

Make sure the vacuum gauge you get has a tattle tale needle. This is a needle that will stay at the highest reading even when the engine is shut down. You have to manually reset it.

Your pump should be downstream of both filters and IMO your vacuum gauge should be between the 2 micron and the pump. Racor filters (I presume the 500 filter/vortex separator filters) are made to be upstream of the fuel pump.

Ah but if the lift pump is down stream of both filters there is nothing protecting the injection pump from failed bits of the lift pump. Of course you could add a pressure gauge after the lift pump with connections and valves to either side of the 2 micron filter to read the differential pressure across the filter, quite common on industrial applications. I'm not wild about that as it creates more potential leak points for air to get into the system.

[DeepFrz]

Is there no on engine filter? I have also made assumptions about the Racor filters that may not be valid. Just guessin...

[sailorchic34]

Originally Posted by DeepFrz

Is there no on engine filter? I have also made assumptions about the Racor filters that may not be valid. Just guessin...

Oh Drat, I made the rather poor assumption that the 2 micron was just before the injection pump.

Your right though if there is a third filter on the engine. then the pump whats to be after the 2 micron filter, though that would be a pretty high suction pressure across two filters