My tank had one baffle in it,but it only blocked about 30% of the tank, the rest could be wiped. As I said, the removal and sloshing worked very well at getting the crud behind the baffle. It took numerous iterations to get the sloshing and wiping to come clean, but eventually the area behind the baffle was pretty clean. Removing the tank is key to this method.

I also used a vacuum pump to draw several gallons of diesel through the tank pickup. Even after all of this, that pipe had considerable crud in it. Once it ran clean, I was confident that I had bought a number of years of trouble free operation.

4-6 hours total time for the following:
- Remove tank and lines
- Clean tank with sloshing
- Mount tank straps to secure tank
- Replace all fuel lines
- Replace tank vent line
- Clean main separator/filter
- Clean small filter
- Draw fresh diesel through pickup line until clean
- Bleed and test (started right up!)

A fairly small investment in time for a very thorough cleaning.

Rich

My inspection plate appears to be sealed with a tar-like substance. What did you use to reseal yours?

On Rhapsody the plate at the top of the fuel tank has a rubber like gasket and appears to be custom cut by a previous owner.

I was mistaken about the baffle on 9/3/09; there is one in our 1984 model fuel tank about 1/3 from the front.

Unfortunately we ran the fuel tank dry during our Fall Series. This resulted in intermittent fuel starvation the rest of the season. After refill and bleed, the engine would run for 3-4 minutes or longer then then conk out. If you pressed the drain valve on the bottom of the Racor filter there was a sucking sound indicating a block back toward the tank.

Engine ran fine on clean fuel in a portable tank for the trip to winter storage. After pumping out the main fuel tank I blew compressed air from a portable pump from the engine side of the hose back into the tank.

Fuel pickup tube appears to have been getting clogged on a hard white sludge with some bits about the size of a quarter, probably a fuel bug. We regularly use Biorbor JF Diesel Microbiocide and Sta-Bil over the winter though typically not added at the same time.

Cleaned what I could reach with Acetone, but there's no way to get past the baffle. Will see if this was enough in the spring.

By the way, there is a fuel shut off valve near the top of the tank that I never noticed before. It's hidden under the lip of the settee.

Bob - That fuel shutoff is per AYBC standards.

Instead of acetone, try pumping good fuel back into the tank using a small pump. Disconnect the hose from the engine side and connect it to the small pump discharge. Then pump about a gallon of clean fuel to get the sludge out of the pickup tube. Once that is done, use a flexible hose and small pump to get as much stuff out of the tank from the inspection port. Mark Rotsky on Nemesis gave me this tip.

Bob,

You could add an inspection port on the other side of the baffel. I did this to repair my tank by the pickup (cheeper than a new tank).

When I first started my rehab of Conundrum last Spring, the fuel had not moved for 5 years. So I pumped out the remaining fuel and cleaned out the entire system with kerosene. This was recommended as a nonreactive solvent to the diesel fuel. Inside the tank I accessed the inspection hole and using a new toilet brush and rags, and kerosene, I cleaned and cleaned. I used a large syringe to backflush the lines from injectors all the way back to the tank taking apart each section that I could. I replaced both the yanmar filter and the racor filter elements. I pumped out all the excess kerosene and wiped everything I could completely dry. I reached as far back behind the baffle which sits approx 1/4 way back into the tank with a coat hanger and a rag SECURED to it. My results were quite satisfactory.




I filled the tank with fresh diesel added a bit of Biocide and I bled the system while hand cranking the engine. I then started the season with the first turn of the key (Push of the button)and she has started and run perfectly ever since.

Wow Conundrum, that's clean! I had acetone on hand and figured it would evaporate. Based on the suggestions, come spring it will be a kerosene wash, then a couple gallons of diesel pumped through the whole system. Rinse and repeat.

Cutting a second inspection port is probably beyond my tool or skill set and I don't want to pull the tank if I don't have to.

Good plan. Acetone is hard on the rubber, not to mention the lungs and skin. Absorption is a leading means of poisoning. Wear gloves too.