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frank
07-09-2008, 12:03 PM
I am giving some thought to installing one on my boat. I have 3 tanks. Has anyone done this w/positive results?

MikeP
07-09-2008, 12:18 PM
If you have DDs, they are polishing fuel anytime they run since about 75% of the fuel that goes thorough the filters to the engine is returned to the tank.

Therefore, if you want to polish fuel when the engs are not running, you can install a priming pump if you don't already have them, a couple of valves/lines, and have complete polishing AND priming system for a lot less money. Priming pumps are invaluable for easy filter changes with no hassles with bleeding, etc. If you already have them, then just adding a few fittings will complete a "polishing" system.

Whether routine fuel polishing is of any use in a boat that sees regular operation is open to various opinions...

Genesis
07-09-2008, 12:47 PM
I think my fuel filter replacement (including polishing system) article is here somewhere. I KNOW its on BoatDiesel. It worked REALLY well and the incremental cost was just a few valves and a Walbro pump, giving you "free" priming at the same time.

MikeP
07-09-2008, 01:38 PM
Just to add - I changed my filter system to the same thing Karl (Genesis) used based on his recommendation/the article he is referring to.

Here's the link to what I believe is the correct post: http://www.samsmarine.com/forums/showthread.php?t=1500&highlight=Genesis+filter

krush
07-09-2008, 03:06 PM
You say the Walbro kicks off at 4psi. That is not much, and doesn't sound like it will flow much through low micron filters.....unless it is a postive displacement pump.

Genesis
07-09-2008, 04:45 PM
It is a positive displacement pump with variable-speed drive.

You MUST have a check valve across it so when the engine is running it can draw AROUND it - it will NOT flow enough fuel to feed a Detroit.

REBrueckner
07-10-2008, 11:41 AM
I also considered a fuel polishing system when refurburshing my YF also with three tanks about ten years ago. I ended up deciding I had other higher priorities but different people and different boats operating under different conditions can reach different conclusions.

I had lost fuel in one engine due to an empty tank once, and after running my other engine with it's return line open to the empty tank to refill it, my starved engine started within ten seconds of cranking with only about 20 gallons in the tank. And while I have had at least one load of dirty fuel in ten years, a few RACOR changes one season seemed to take care of it. I concluded I did not really need fuel polishing.

Another consideration is that if you have significant quantities of fuel aboard and don't use it for several years, polishing can help extend it's useful life especially in tropical climates. Under that condition however, using a fuel storage additive would be wise anyway.

If you are cruising full time in unfamiliar areas or remote locations where fuel quality may be an issue, a polishing system can be useful and a preventative maintenance even if you use your fuel regularly.

(Nobody You Know)
07-11-2008, 09:44 PM
Keep in mind that fuel polishing is very limited in it's ability for thoroughness. Baffels in your tank restrict the effectiveness of the polishing system to perhaps as much as one third of the overall tank. And it can be very expensive too.

frank
07-11-2008, 10:02 PM
thanks for all your input...I think I'll just carry alot of racor filters!