How many fuel filters are enough?

[Don S/V ILLusion]

Not sure how well this picture will display but hopefully you can make out 2 of my 3 fuel filters on left, the first being the typical racor 220 with the clear bowl, the second adjacent filter which is pretty obscured, is a copper/bronze metal Racor 110 which is also a fuel/water separator and filter and the last "secondary" is on the Yanmar.Anyone think it's worth having 3 and if so,why?I'm tempted to just remove the middle one and eliminate the connections and need to change this filter.Don

 

[Rick D]

I have the stock 220

...and don't know what purpose the other would have. You still have the engine filter too. It would make sense if there was a way to switch between the two if the 220 failed, but your description would seem to indicate they are in series, in which case, I'm puzzled. I'm sure there are smarter guys on this site who can figure out why it's a good idea tho. Rick D.

 

[Dan Johnson]

Don...

When I bought it, my H34 had a Racor 220, a Perko water separator, a Bio-cide thingy and a vacuum gauge ahead of the Yanmar filter. We had fuel problems last summer and I'm in the process of leaving just the Racor and gauge between the tank and the engine's filter. I'm adding a squeeze bulb to aid in bleeding the system. When I opened the Perko thing up it was filled with black gunk so I immediately bypassed it to take it out of the fuel flow. I also will be installing an access port in the tank to clean it out. I built a fuel polisher and will polish all the fuel before starting back up this spring. The Racor is a 2 mic one and the Yanmar is a 10 mic one. Better to have the Racor clog and signal by the gauge the need for a change then to have the Yanmar one pass junk to the injectors. Also, one filter is easier to replace than two.If you keep both Racors, make one a 10 mic and put it closest to the tank, then use the other as a 2 mic stop-gap. Put a vacuum gauge between them to spot the first one clogging up.

 

[Bill O'Donovan]

Two is plenty

I just attended Yanmar School in Deltaville, so now I'm a certified know-it-all. Instructor advised that the primary is designed solely to catch water, while the secondary at the engine is designed to catch trash. If the right filters are selected for each cannister, you should be good. Anything else may be overkill.

 

[Fred]

I have seen installations with two filters

(not counting the small in line filter supplied with the engine)on fish boats and commercial vessels that were set up so if one clogged, you could close some valves and switch to the other filter, allowing the motor to continue to run while you service the clogged filter. Especially with big tanks on older boats, in rough weather crud (to use the technical term) can get stirred up and clog filters when you need the motor most.Look for old fittings and hoses or hose brackets that might indicate that your filters were set up to be isolated.

 

[Steve Dion]

Two primary's is an excellent margin of safety.

Bill:While a single primary and a secondary is an good system it is not an optimum solution for an older boat that may have comtaminated fuel system.If you have a contaminated tank (which you may not know that there is a problem) and you are out in rough conditions there may not be enough filtering capacity with a single primary filter.The optimum filtering system is two primary filter with a bypass valve that will allow the switching from one primary filter to the other. This will allow you to switch from one filter to the other. This will also give you the option to switch to the alternate filter while changing the other.This can be a life saver in the right conditions.The other option is to keep you tank clean (not always an option).