Racor filter service interval

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Oldslowandugly
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Location: Queens NY

Racor filter service interval

Postby Oldslowandugly » Thu May 23, 2019 10:32 am

I know Prudence would say change out the fuel-water separator filter every year as a minimum. I had suffered water in the boat’s fuel several years ago, and I installed a Racor 10-micron fuel-water separating filter as a precaution. I wanted to know how long it took to clog so I left it in place for two years with no problem.

This year I put the Whaler in the water and motored 5-miles to the slip again with no problem.

But yesterday on the first fishing trip I got about 10-feet from the slip when the engine began to cough and shake. I thought the spark plugs could be fouled, but as soon as I returned to the slip I remembered that the filter was old.

I removed the filter fuel line and jumped the fuel tank line directly to the motor. I have small inline filters on each fuel line as backup just for this scenario.

After several full throttle pulls the engine smoothed out and ran normally.

My takeaway from this is that even though I got two years of service from the filter I probably should change it out every year just because. Perhaps the 10 micron fouled quicker than a 20 or 30 micron would have, but I think the finer filtering is worth it.

jimh
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Re: Racor filter service interval

Postby jimh » Thu May 23, 2019 11:56 am

The time to change a fuel filter is just before the media in the filter reaches a state of clogging that the suction pressure required to pull fuel through the filter will exceed the maximum allowed value stipulated by the engine maker.

The suction pressure can be monitored with a vacuum gauge that is Tee-ed into the fuel hose at the filter output.

RACOR makes gauges for that purpose, but there is a bit of confusion on their rating for use with gasoline fuels.

One gauge with a dial pointer indicator has a follower pointer that will show the peak vacuum pressure that has occurred. The peak suction pressure usually occurs at high flow rates associated with high throttle setting on the engine.

If you wait for the filter media to become completely clogged, the suction pressure was probably too high for a while before the media was filled. With any engine, running with lean fuel-air mixtures can cause problems with too much heat in the combustion chamber.

jimh
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Re: Racor filter service interval

Postby jimh » Thu May 23, 2019 11:59 am

The time required to clog a filter will depend on the media opening, the amount of filter media, the amount of debris in the fuel passing through, and the volume of fuel.

To clog a big RACOR 10-micron canister filter it might only take a few gallons of fuel with a high debris or water content.

Oldslowandugly
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Location: Queens NY

Re: Racor filter service interval

Postby Oldslowandugly » Fri May 24, 2019 10:35 am

So in lieu of plumbing in a vacuum gauge can I assume that changing the filter every year will probably eliminate the possibility of clogging during the season? I figure if it went two years and was marginal the second year then one year should be non-eventful. I have cleanable in-line filters on each fuel line before the Racor just to catch gross debris. I believe they have 20 micron elements. I left them in place to pre-clean the fuel before it reached the 10 micron Racor. I believe they call that "polishing". Yesterday when I went to change out the filter element the drain bowl would not come off. I followed the directions to remove the filter and bowl as a unit, then remove the bowl. I held the element with a strap wrench and used the proper Racor wrench to grab the bowl. But the plastic threaded ring part on the bottom of the element just spun. Luckily the Dock Master was around and he let me clamp the element in his shop vise. After I crushed the element enough to pinch the plastic ring the bowl came off. I guess that is another good reason to change out the filter element ever year at home where I can deal with such problems.

Oldslowandugly
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Re: Racor filter service interval

Postby Oldslowandugly » Sun May 26, 2019 7:12 pm

UPDATE: It may have not been a clogged filter. I went out today and again as soon as I left the dock the motor stumbled and wheezed. This time I headed right back and pulled the spark plugs.They were clean as a whistle. So it was not ignition or the filter causing this. Again I by-passed the filter and ran the fuel line right to the motor. Again after a few WOT blasts it ran great all day. I can't imagine the filter failing in one day so after fishing I double checked everything. All I could find was with the in-line filter I have in the line going from the Racor unit to the engine, I could screw the filter fitting farther into the filter itself. Perhaps the fitting was loose enough to allow air to be sucked into the fuel line? I won't know until I run it again but if so that is a new one on me.

Oldslowandugly
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Joined: Fri Jan 15, 2016 11:19 pm
Location: Queens NY

Re: Racor filter service interval

Postby Oldslowandugly » Wed May 29, 2019 7:56 pm

UPDATE: I went fishing today and the motor ran great. So maybe the turn-and-a-half loose filter hose nipple was the culprit? I will wait and see because it was intermittent and fooled me before.

dtmackey
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Re: Racor filter service interval

Postby dtmackey » Thu May 30, 2019 10:45 pm

On my 15 Whaler with a carb motor I do not run a filter since a carb can take quite a bit of gunk with no problems. I also started with a fresh fuel system last year.

On my Mako 21 with an E-TEC 250 I use a water-separator RACOR, and it is changed every other year. The filter on the engine is changed annually.

On my 32 Nordic Tug (diesel engine) I only change the large RACOR filters when the vacuum gauges on the filter indicate that it needs changing. The fuel was polished four years ago after it sat for an extended time, and the process removed lots of gunk.

A good rule of thumb is not to over-filter more than the engine manufacturer called for.

The fuel system on a diesel is very different than an outboard, and it's very common to run the vacuum gauge on the filters. The problem with attempting to run this on an outboard is there are so many variables between carburetor engines, DI engines, four-stroke engines, and more, so I'm not inclined to run [a filter and vacuum gauge] type setup on an outboard.

D-

Oldslowandugly
Posts: 392
Joined: Fri Jan 15, 2016 11:19 pm
Location: Queens NY

Re: Racor filter service interval

Postby Oldslowandugly » Sun Jun 02, 2019 9:18 am

I went out again yesterday. The motor ran fine. I can't believe that a turn-and-a-half tightening of the hose barb cured the [fuel flow problem]. Live and learn.

[There are] filters on both fuel tank lines for just this reason, that is, if the main filter is clogged or otherwise disabled, I can bypass it and still have filtered fuel getting to the engine.

Now I have to ask myself: do I want to discover how long I can go without changing the Racor filter again?

dtmackey
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Re: Racor filter service interval

Postby dtmackey » Sun Jun 02, 2019 10:03 am

If the Racor filter uses the clear bowl or tinted blue bowl, be advised a product bulletin was released in 2016 to change these to the newer design that appears to have a yellow tint and it ethanol compliant. The old bowl will fail when E10 fuel is used over time.

https://www.parker.com/literature/Racor/Service/EB00033_Marine_Gasoline_Spin-on_Filters.pdf

D-

jimh
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Re: Racor filter service interval

Postby jimh » Sun Jun 02, 2019 11:54 am

DT--thanks for posting the link to the RACOR advice regarding fuel filter bowls and their service life with ethanol-gasoline blended fuels.

I need to inspect the RACOR filter on my boat. It has a bowl. The filter location makes visual observation of the bottom of the bowl difficult. Maybe I can get in there with a smartphone camera and check for the "PUR" "Z" markings. I have had that filter and bowl in service for many years. I have never seen any debris or water in the bowl. It's due for replacement just on length of service, although I really don't put more than about 50-hours per year of engine run time; and a lot of that time is at a low fuel flow rate. The total fuel run through the filter per year is perhaps 250-gallons.

Oldslowandugly
Posts: 392
Joined: Fri Jan 15, 2016 11:19 pm
Location: Queens NY

Re: Racor filter service interval

Postby Oldslowandugly » Mon Jun 03, 2019 8:55 am

DT- Yes, I read that while shopping for the filter. I made sure the one I got was the yellow tinted model. As Jim said, I too have never found even a drop of water in the Racor bowl. Yet, several years ago I was stopped dead in the water from contaminated fuel. My small in-line filter was full of water. Luckily I was able to switch tanks and be on my way. That is why I invested in the water separator. Has anyone ignored their filter for many years? If so how long was it and did they finally clog?