Fuel filters

[John Reid]

Two fuel filter questions (Yanmar 3QM30):1) I have a Racor primary. When I bought the boat the filter on it was an R24SUL. When I went to replace, the yard I was at told me to use a finer grade filter (I don't recall the number). I was a bit skeptical because the finer grade filter was the only one they had in stock. Do you have a recommendation for the Racor element to use with this engine?2) I have a leak at the Yanmar secondary fuel filter; it sounds just like what's been described in the post below ("Yanmar diesel fuel leak at fuel filter"). I've replaced the copper washers and I've replaced the bowl. Still leaks. Any suggestions for troubleshooting leaks at the secondary? What about the suggestions in the previons posts to use teflon or liquid goop.?Thanks.

 

[Bryan C.]

2 microns clog

I put a new Racor(small one) on my 35 (3GM30F) when I got her. Forget the model number of the filters they had (10S?) but they were 2 micron filters which would clog up after a couple weeks, usually at the most inopportune times. Ordered the 10micron model (10T?) and it worked great for a year. I think the secondary filter on the engine is a 2 micron filter so you're covered.

 

[Dave Ullrich]

Never had a problem with 2 micron filters.

I've been using Racor R24S elements (2 micron) in my 220 seriers filer/separator for over 5 years and have never had one clog to the point of stalling the engine. Sometimes the engine won't rev all the way out, but this only tends to remind me to change the filder. Even when it is due for a change I am able to get 4.5 knots out of my Universal 5411 (11hp). I usually only have to chage my filter element once a season, and drain the bowl once or twice a season. When the filers are clean I cruise at 5.5 and top out around 6 knots on flat water using the original 2 blade prop.If yours clogs constantly with 2 micron filters, I'd sugges getting that tank cleaned out. Comapnies such as Q-Lube can pump all the fuel and gunk out and "polish" the fuel. It comes out with less debris than it wnt into the tak with. Q-lube charge $1/gal to do it here, and I get it done every other season. Also, make sure that you put water remover and biocide in the tank.

 

[Stevec]

A second vote for Dave

Have the same setup on my boat only I must be getting better fuel than the rest of the guys (oh crap - probably just put the kiss of death on the fuel tank). Filter never clogs or causes any kind of fuel related problem. Never have to drain it - replace it every 200 hrs whether needed or not(this translates to every other year).

 

[Gordon Torresen]

Fuel filters - why?

Fuel filters are in the circuit to stop anything but fuel from getting to parts that could be harmed. If your filter shows anything foreign when it is changed, its time to work on the fuel tank. If you have to drain water from the tank, its time to get the water out of the tank. Water dispersants and/or other additives can have a negative affect on the combustability of the fuel.  Cleaning a fuel tank does not necessarily require removing the old fuel, unless it has been contaminated by something mixed with the fuel, ie additives, gasoline, etc. Water does not mix with the fuel and can be removed by pumping the water from the bottom of the tank. Algy lives in the water and it too can be removed from under the fuel although it takes longer for the algy to move to your target area.  A very important point, if you find water in the tank, is to stop it from coming in again. The usual way for water to get into the tank is past the O ring on the fuel fill cap. This should be checked at least every time you add fuel. The slightest crack or distortion observed, put a new ring on and keep checking it. We were once alerted to an O ring problem on new boats and installed new rings immediately. The boat builder supplied us with replacement O rings which we put in stock. Not long after, a customer came in to buy an O ring and it was found that the "new" ones on the shelf had cracked. KEEP CHECKING THE "O" RING. "Polishing" fuel will remove contamination floating in the fuel but it will not remove what is under the fuel. That's the stuff that causes trouble. There can be quite an accumulation because the pick up tube is generally off the bottom of the tank. It will show up when motoring in a seaway. The water and/or debris starts to move around the bottom of the tank and forms waves that can impinge on the elevated pick-up tube.  Keep the fuel tank clean and rely on the filters to forcast fuel problems.