We bought #1494 last fall. I pulled the tank and got it cleaned because I believe any boat that old with a tank that's never been cleaned is a fuel problem waiting to happen. Plus the Racor had about an inch of black crud in the bowl.

When I poured the last fuel out that was below the pickup it was black yutz and didn't look or smell much like diesel. I had the tank cleaned by a rad shop that does that kind of work.

Personally, I do not believe fuel polishing will get all the crud out of a tank. Polishing likely will keep fuel really clean once the tank is clean, but I do not believe it can get the stuff out that is solidly stuck to the sides and bottom. Your fuel pump kind of polishes the fuel all the time the engine is running, it pumps far more fuel than the engine can use and that excess fuel goes right back into the tank and is recirculated again and again.

BTW, for about the same charge your marina wants you can buy a micro polishing unit from Parker (Racor).

I put an article in here on pulling the tank, it's pretty simple to do.

Elliot,

I posted a recent thread with many responses regarding my blunder of putting a water hose in the fuel tank instead of the water tank. I had the yard company (WYS) do the job. I thought they were going to polish the fuel, but instead they pumped the tank dry and refilled it with new fuel. They assured me in the process they removed all crud on the bottom and that my tank should be very clean. I have had very good luck with these people in the past, so I accept there comment. They also changed both the primary and secondary filters. The bill which included 3 hours of labor was just under $400. That was a very costly mistake, but I feel better knowing that I have a clean tank. Good luck.

Wow, for around $400.00 you can install your own on-board polishing system that runs anytime the engine does. Please remember many fuel tanks have chambers and baffles. It is nearly impossible to "clean" a tank and it's walls without scrubbing it and installing clean outs. This does not mean a "polishing service" won't help, it may, but it won't "clean" a dirty tank that is baffled.

This stuff does not come clean with "polishing"..
[IMG]http://www.pbase.com/mainecruising/image/123035293.jpg[/IMG]

Is that pitting in that picture of the tank? Is that a pic of the inside of a C36 tank? If so, doesn't look like a cleanout would be the end of potential problems. I had the fuel pumped out of my tank until it was empty, then refreshed with fresh fuel. Was going to go the polish route, until we agreed that just pumping out the remaining 5 gallons or so and replacing it, would be more effective. Obviously neither is going to do anything about that pitting.

My boat is 13 years old, maybe I should consider replacing the tank this fall, or at least getting the inside inspected to see if there's significant pitting. I'd hate to have fuel in my aft cabin.

I agree with Bud and noticed that a decent quantity of fuel is circulated by the fuel pump and the excess not used by the engine goes back into the tank. I had previously been thinking about going to a fuel polisher. With these recent threads, it would appear that a scheduled cleaning of the entire tank is worth the peace of mind to know that there is definately no crud left.
John Meyer
2135 Hilbre

Just reading what everyone is talking about and the fuel issues here makes me wonder if anyone else has installed an Algae-x Unit. I installed one over 4 years ago and have not had a bit of a problem with our fuels or tank. I am just reporting here what I have experienced over the last 4 years and how clean it has been. I have not replaced a fuel filter in that time either as I installed a vac gauge at the same time as the Algae_x unit. Now take in consideration that we live in Michigan and it does get cold in the winter. Our tanks are full during that time but I also use a diesel treatment that Caterpillar recommends.

Our stern has been much cleaner sense I installed the unit. I will tell you before I bought the unit I was very skeptic just as everyone else was looking at it. But now that I have it in place all I can say is that it has worked for me. This summer we will give it a good work out as we are leaving for the Bahama's in less then 2 weeks and should go through quite a lot of fuel I am presuming.

[URL="http://dieselfueldoctor.com/solutions_explained.html"]http://dieselfueldoctor.com/solutions_explained.html[/URL]

Randy, where did you put the vacuum gauge? I think that is an excellent way to monitor what is really going on with the fuel filters but have no idea how I would install one.

Bud :

I have the gauge installed between my racor filter and the motor. I cut in a tee fitting into line and added the filter in the tee. I have to pick up the cushion and cover to check it but it is a quick check. But there is still the spin on filter on the motor. So basically it is monitoring the racor filter. Hope this helps

[QUOTE=mutualfun;5718]Bud :

I have the gauge installed between my racor filter and the motor. I cut in a tee fitting into line and added the filter in the tee. I have to pick up the cushion and cover to check it but it is a quick check. But there is still the spin on filter on the motor. So basically it is monitoring the racor filter. Hope this helps[/QUOTE]

Just be sure you are monitoring the vac gauge at or near wide open throttle while under load. You can't effectively check them at idle.

If in the market for one I would highly recommend the drag needle type that moves a second needle with the read out needle and leaves it where the needle peaked.
[B][URL="http://www.sailorssolutions.com/index.asp?page=ProductDetails&Item=VG01"]
Sailors Solutions [/URL][/B]sells a drag needle vac gauge.
[IMG]http://www.sailorssolutions.com/ProductImages/VG01KT_1.jpg[/IMG]
P.S. You will also want to benchmark your vacuum gauge. To do this run the engine at or near WOT and monitor the gauge with know clean filters and write down the RPM at which you checked this. If the needle does not move note this. If it moves up one click note this. From this point forward if you check the VG at the same RPM, under load, and the needle is in a different position you know your filter is beginning to plug.

Oh and if you change the micron rating of the filter you'll need to benchmark again as a 10 µm filter has more restriction than a 30 µm.

Excellent points, Maine Sail. Thanks!

Even under full load - At least when everything (fuel etc) is fresh and new and your tank is clean. I have just a 2 micron filter as my Racor Filter (I know it should be bigger - thats another discussion) and I have the vacuum guage and even under absolutely full load I cannot get my vacuum gauge to move beyond "0". I was so concerned my vacuum gauge wasn't working that just to make sure I "pinched" the fuel line from my tank to my Racor filter just to see if the vacuum gauge was working. (Yes and when I pinched the fuel line the vacuum started to creep up).

So I can tell you when things are new you should see "0" vacuum and the needle wont move, even under full load.

Tom:
I was in the same boat, that was going on with me and I had to rethink things. So I did the same exact thing with a pair of channel locks and pinched the line off. I do not know if it is the colder climate that we are in that does not grow the fungus in the diesel fuel or what. But I have heard it is worse in warmer waters.
Randy

[QUOTE=tsenator;5724]

So I can tell you when things are new you should see "0" vacuum and the needle wont move, even under full load.[/QUOTE]

Tom,

I only mention the needle moving because I have installed a fair number of VG's on a wide array of boat/engine combination's. Depending upon fuel pump flow, elbows, hose DIA and restrictions, pick up screens in tanks etc. etc. the gauge can read higher than zero on some installations even with a brand new filter at WOT or cruise RPM under load. I have not installed one on a MKII with the bigger engine so was unsure how it would or should read. I am glad to know it is 0.

It can also depend where in the system you install it. If you install it after the secondary filter you will likely get a reading at load. Most install them on top of a primary Racor 500 series. The small Facet pumps are low flow so generally speaking it should read 0....

Not much fuel vacuum created by the small electric pumps we have on the M35's. I do know most people put the vacuum gauge on the primary racor filter on the outlet side. So it will only let you observe restrictions "upstream" (Racor Filter, hose back to fuel tank and pick up line in fuel tank)