How to 'Get By' / Diagnose Fuel Problem ?

[donradcliffe]

My pappy taught me to always check the cheapest and easiest things first. The fact that you were able to wait a bit and motor for another few hours means that the problem could be a blocked fuel tank vent. The next time it starts to die, the first thing to do is to crack open the fuel tank fill-if you hear a whoosh and the engine is happy, you have found the problem.

[sgtPluck]

Turns out it was not the fuel vent, it is sludge, although I'm not sure how much.
I found a place here that will put an inspection port in the tank, manually clean the tank, and also scrub/polish the fuel. So I think I will bite the bullet and get it taken care of.

The only concern is, the 6" plate will probably not fit in the top of the tank so they'll have to put it on the side. Is this ok do you think? The guy at the tank company seemed to suggest it was preferable to put it on top, but he could do it on the side if need be.

[DeepFrz]

I have seen them installed on the sides of a trawler's tanks with no problems. Certainly I would prefer the top but that is just not possible on some tanks. Any clean out port that doesn't leak is preferable to none. Good luck.

[Eleven]

I'd considered, and not got around to, adding an electric recirc pump to my tank so i can clean debris from fuel and remove water/gunk.
I like the day tank approach better, especially if it can be above the engine for gravity feed. A simple return line from the bottom of the day tank to the main tank will guarantee clean fuel to the engine, but the electric transfer pump is still necessary.
Best option will very much depend on the layout of your boat. A winter project perhaps.

[DeepFrz]

Eleven, I don't want to go to far off topic here, but in my opinion your ideas are not necessarily either/or. Both might not be a bad idea, but certainly a fuel polishing system is worthwhile. Maine Sail has some interesting pictures about his system installed when he installed a new fuel tank. Worth having a look at.

Replacing A Fuel Tank Photo Gallery by Compass Marine at pbase.com

[svcambria]

I installed a one cylinder Kubota diesel for a generator, with a fuel lift pump, and an unintended consequence was that about four times as much fuel was pumped to the unit than needed, all of it going through a Racor filter, which polished the fuel as the generator ran. Using diesel actually kept the tank clean...

Michael

[DeepFrz]

Michael, now how much fuel did that little pump really move through your filter? A fuel polishing pump should move a lot of fuel and the system should really be separate from the fuel feed to any engine.

[svcambria]

It is an "interrupter" pump, running from 2 to 5-ish psi, my imperfect impression is it moves about 1/4 gallon per minute, so if the generator runs for an hour the lift pump moves about 15 gallons of fuel with most of it being returned to the tank. The Racor filters the fuel as it goes through; by volume the 55 gallon tank would be "completely" filtered in about four hours of generator use. The intention was to supply fuel to the generator; the by-product is that the tank fuel gets filtered. Ideally the tank should be agitated with high pressure return to mix everything up, but I will take what I can get - especially as windfall...

Michael

[sgtPluck]

For the record, this was the outcome of my situation...
I had an inspection plate installed today, and we manually cleaned out the tank. There was a little bit of sludge in there, not much. However, the nylon pickup line was almost flush with the bottom of the tank, leaving a very small gap for what sludge there was to plug it up easily. We clipped a small bit off the bottom of the pick up hose.
I'm hoping I should be all set now, I'll add a bit of biobor every time I fuel up.

[barnakiel]

Sounds like dirty fuel.

b.

[Eleven]

You may remember that Richard Bransome's ttransatlantic power boat record was hit by dirty fuel problems following a quake which caused the fuel carry a lot of sediment that blocked the engine filters.
The first thing to do, given that proper fixes involve a bit of work, is to add a second fine filter in parrallel with the current one and add tee valves so it's a quick change over and will allow the non-active filter to be changed while the engine continues.
Don't have a system that can allow both to block.