Diesel Filter/water separator

[Gulfislander]

Hi Experienced Cruisers. This newby needs some advice. My boat has a 3 year old Yanmar 2GM20FC. The fuel filter/separator is original (~28 years old) and needs replacing. I want to replace it with a good system that is easy to manage (ie find and change filters). I cruise in the Pacific Northwest only. Any Advice?? Thanks in advance.

[Chief Engineer]

I would reccomend the Racor 500 series...spend the extra $$$ and get the vacuum gauge......use 30 micron filters and let the small filter on the Yanmar be your secondary

[kelpline]

When I found that the Yanmar primary filter cartridge was C$125, I found a Racor 500 in a garage sale, bought a one-way valve to place before the racor housing, then tossed the Yanmar filter housing. The Yanmar housing had its water sensor terminals too low, at the bottom so every tea spoon of water sets off the "water in the fuel" alarm. For the Racor I bought six 30 micron filters for C$15 each, and let the one micron secondary Yanmar filter on the engine do its work. Every second day I eyeball the sight bowl of the Racor for water, and drain it when some shows .

[Compass790]

:https://www.aliexpress.com/item/3293...archweb201603_

Above is plenty for your engine. Racor 500's are overkill IMO but if you have lots of $$$...
Invest in a filter funnel for tank filling & a new o-ring for your deck fill cap.

[a64pilot]

If your getting water, ever you have a problem that needs fixing, you should never get any water.
I’d start with the cap O-ring myself, and I’d take my oil change pump with the little tube and suck fuel from the corners of the tank to see if you have water in the tank, which you pretty much have to, to be seeing it the filters and it needs to come out.

[NYSail]

Yea.... been boat owning for 20+Years and never emptied any water. Racor 500 with 30 micron filter, New fuel tank gasket and call it a day. Check weekly.

[kelpline]

Thank you all for the great advise, I will check the cap's o-ring. My boat had the fuel tank set bow down, so the problem showed up when the boat came onto plane. I loaded 1400 lbs of water onto the swim grid in a 45 gal drums and garbage cans, but still could not get the fuel tank level. After severaL suctions with the shop vac and oil change pump, testing with Kolor Kut water paste showed that very little water remained in the tank.

[Marathon1150]

I strongly agree with the Racor 500 recommendation but I use a 2 micron filter in the primary and secondary filters. This way I don't need to think about which filter is plugged - I change the Racor and leave the secondary filter alone.

On a Perkins 4.108 changing the secondary filter when it plugs at the worst possible time, is a major hassle that more often than not requires bleeding the entire system. I fill the Racor 500 with a small electric fuel pump plumbed into the fuel line so changing the filter usually takes less than one minute. No bleeding necessary.

I also filter everything going into the tank with a water separating filter. During the 15 years of using this system, I have had two problems. Some sludge from the bottom of a jerry can went into the filter but I wasn't worried about it until the filter cylinder that sits in the middle of the filter came loose and let the sludge go into the tank.

Next, we had our fuel polished and tank cleaned and it is very likely that the guy who did the work, left a paper towel in the tank. Here is what we found inside the Racor where there is a little ball with appropriate density to prevent water from getting through it. Water wasn't the issue in this case:







I have followed the debate on 30 vs 20 vs 10 vs 2 as a primary filter for a long time and I am quite happy with this set up. I am sure that many others will definitely have a different view.

[Dalestr]

Having any measurable water in the tank invites algae growth so it is best to suck all water out from the low points of the tank. While the Racor 500 filter is great you need good access from above (top loading). It must be filled with fuel before sealing the lid and can't be bled. Smaller filters like the 110A or the 200 series are plenty large enough for a 16hp sailboat engine. I go three years and could probably go twice that between element changes but this depends on quality of the fuel source. I have the same engine and use the 110A. Consider how you will prime after a filter change or a run dry event. You likely need a priming pump for the primary. I use a primer bulb but some insurance companies don't like these (or unshielded plastic filter bowls either). The 200 series spin-on filters have integral pumps. These filters do need a strong mounting as it takes a lot of torque to free them.