Raycor fuel filter

[tjandoverguy]

how do you know when the filter dosent filter anymore
does the bowl show debris

[skipmac]

You might or might not see actual debris (and/or water) in the bottom of the bowl, depending on what is clogging the filter.

The best way to determine the state of the filter is with a vacuum gauge. There should be a fitting on top of the Racor where the gauge will screw in.

[tjandoverguy]

ok i get a vacuum gage what should read

[skipmac]

Sorry I forget the exact numbers.

If you get the Racor gauge then the low to middle of the dial is normal. If the needle goes high on the scale that means the vacuum is higher which means the engine is having to suck harder to get fuel through the filter meaning the filter is clogging.

I just glance occasionally to see if the needle has moved and if it is still in the middle or lower. If it move to the high side of the scale then time to swap filters. Increase in vacuum is as important as the actual number.

[skipmac]

https://www.parker.com/static_conten...um%20Gage).pdf

[Group9]

Originally Posted by tjandoverguy

ok i get a vacuum gage what should read

We have a vacuum gauge that screws onto the top of our Racors that actually tells you when to change the filters. I have found it to be pretty accurate (in that it indicated change was needed one day, and I thought I could make a short trip anyway, and about two hours later, one engine surged and died, and then ten minutes later, the other one, did, LOL).

[a64pilot]

Interesting, that looks like an air filter restriction gauge, most vacuum gauges on Racor’s are round dial gauges.
What they will indicate will depend on the boat, even with a perfectly clean filter mine reads kind of high as my fuel tank is lower than average and it will read higher on an almost empty tank than it will a full one. The reason is of course the lower fuel level means a higher vacuum is required to suck the fuel up to the filter.

[a64pilot]

Originally Posted by tjandoverguy

how do you know when the filter dosent filter anymore
does the bowl show debris

The answer is that the filter will always filter, but it will eventually clog to the point that the engine won’t run, then you put in a new filter.
The Vacuum gauge if it’s a good one has a “tattletale” which is another pointer that stays at the highest vacuum achieved, if you run a filter until fuel starvation starts to happen, then you know how much your boat and engine will pull vacuum wise then you decide just how much restriction you will accept, and change the filter before you get there. Vacuum will be different based on engine load, so at idle you will have a lower vacuum than at high power, that is why you need the tattletale, cause you don’t want to have to go below to look at the thing when the engine is running hard.
I have two filters so I can run longer because if I get into fuel starvation I flip the lever to the other filter.
The red needle is the tattletale.
You can also just change filters at some interval like we do oil filters, say once a year, that’s easiest and you don’t have to buy a vacuum gauge. However carry spares cause filters are known to clog when you least expect it, and without a spare your options are limited.

[tjandoverguy]

thank you for all the replies

[Lepke]

Any vacuum gauge will do. The actual vacuum numbers will vary depending on the Racor model and the volume of fuel passing thru. Filters usually last much longer than most people think.
I have twin Detroits and Racor 900s. My engines pump about 70 gallons/hr. I use a 2 micron filter element and my vacuum reads zero when the element is new and 7" when I change it at about 500 hours.

[Simi 60]

This type which is on our 1000 series apparently reads + or - 20 , depending on which side, when clogged

Ours always read 0 but the gauge does work as I have slowly shut down fuel as a test