Detroit Diesel/Fuel Question

Ocean,
Welcome to the Forum.
When you purchased this boat, you should have done several things, basically due to its age and possible several owners (you may never get a straight answer to any question from a previous owner). First, I would have had the fuel polished and the tanks tested and cleaned if needed. Polishing would have cleaned the fuel and testing the tank would let you know how much gunk was sitting at the bottom. Having done that, I would have changed the filters, so you could then monitor their condition post cleaning. Oh yeah, never trust a fuel guage. If your tanks have sight guages on them, make it a habit of using them. But do make it a habit to note miles/hours run since last fill up so you can guage by range if you need more fuel
So to your questions. It's odd that you could not advance the throttle, and on a 1987 it's probably a cable throttle. Even if out of fuel the throttle should advance. If one engine cuts out it could be that one fuel tank has debris in it and the other not as much (assuming a two tank setup). And if the generator is drawing from the same tank that feeds the engine that cut out, dirty fuel could be the problem.
Depending where the fuel pickup is, you could very well have some fuel in the tank when you run dry. I know guys who had problems with fuel and actually cut the fuel pickup line shorter so they wouldn't get the junk from the bottom, so maybe the tube is too short. Keep in mind that on most two tank systems thgere is a cross over valve to feed fuel from one tank to another, so see if it is open or closed.
Speaking of air pocket, where you running in rough seas before the engine cut out? Was the generator running at that time also? Do you have Racor filters or some other filter that has a sight glass, so you can see if you have junk or water in the fuel? Did you have to prime the engine to get it started after refueling or did it start right away once fuel was in the tank?
Don't forget, when you change a fuel filter you need to fill the canister with fuel before replacing the cap so you don't draw air into the fuel system.
Hope that helps and let us know the answers and we'll try to help more.
Capt Tom

Next time you have your diesel mechanic to the boat ask him to check the inlet fuel pressure you may have a bad lift pump (read cracked diaphram) . It's easier to move air than diesel and when tank head pressure is high, meaning tank level is above filter/pump All works fine but below no go.

Fuel line problem

Hi,
I had a similar problem with my generator.
Over a period of several weeks the fuel line to the generator would develop a bubble and eventually would not run. This caused the fuel pump to fail but after replacing the pump the problem persisted. The lines were tested and found good.
The problem was worse with low fuel levels and rough seas.

The answers were- the generator has a shorter pickup tube and the return lines from the main engines did not have tubes protruding down into the tank. The stream of fuel jetting into the tank caused air to be forced down into the fuel and small bubbles found thier way into the pickup tube for the generator.
After installing return line tubes deep into the tank the problem was solved.

It also helps to always run with at least 1/2 tank of fuel.
Good luck with the "new boat"

Diesel Fuel Management

More than likely you have bad diesel fuel. 90% of problems associated with diesel engines are caused by bad fuel.

You should consider a fuel conditioning and management program for your yacht as part of your preventative maintenance program. Most yacht owners and captains neglect this, however, the engines are the most important piece of machinery on your yacht.

Many captains say, "I burn through so much fuel, that I don't need to worry about it's quality". The truth is, a diesel engine only burns part of the fuel supplied to the engine, the rest returns to the tank to be reused. This process adds to the problems of organic and inorganic debris in your tank, as well as accumulated water in the bottom of the fuel tank.

A yacht should have its tanks cleaned at least once a year, and its fuel conditioned chemically every time new fuel is added to its tanks. In addition, a yacht owner or captain can have inline magnetic fuel conditioning equipment and a bulkhead mounted fuel polishing system added to the yacht's fuel system.

Admin edit: Link Removed!

Hi,

Welcome to YF.

I am sure you don't intend to be a scare monger but have done so anyway.

I agree with Chemical Dosing and carry out this practice myself. I don't agree with the need to clean the tanks of all yachts annually.

If you run a good fuel care program and are careful on where you fill up and what you fill up with you will not have the nightmare scenarios that we read about occasionally.

Bad Fuel? Not!

Of course, fuel condition was my first suspicion. The filters were changed and looked like new.
When I built my boat I had magnetic fuel cleaners installed on the mains and the generator.
I have sucked fuel out of the lowest corners of the tank and found it to be squeeky clean. From experience I know that if any water finds its way into the tank, it will be sucked into the Racor without delay.

The problem was that the generator- Racor was filling up with air.
The fuel pump could no longer move fuel through the filter and the generator dies. The cause was air mixing with the fuel in the main tank because the return lines were squirting from the top of the tank down through air into fuel.

Happy thanks giving

It sounds like you could have several issues going on. I would never leave the dock with a new to me vessel without topping it off before leaving on a trip like that. I am not very familiar with a 44' Ocean, but am familiar with other ones 63' SF, 48' express etc. What did the fuel filters look like when they were changed? Did they look black and have lots of little particles and chunks between the pleats? It is quite common on an older vessel to have to change the racor filters on a regular basis (every 50 hours or so) use 30 micron filters. Make sure the fuel valves are shut before opening fuel filters, and make sure to fill the filter housing with fuel before shutting lid, then open fuel valves.
I manage 12 different yachts in the 40-70' range so I have seen about every fuel issue imaginable. I also do not believe in the need for polishing every year. Also in my experience polishing gets out 95% of the algae, and unless you do a long trip or something and burn through all of that fuel and a few tanks and treat it with something, it will grow right back in the new fuel just as bad as it was in a few months after polishing. I prefer to use Diesel Kleen additive by Power Service, that is the only product I've found that kills the algae and dissolves it. I prefer to use that and change racors over polishing 95% of the time. I had one vessel I managed with 2 year old fuel in it that I treated with diesel kleen, In 50 hours at cruise (a 5 day delivery) I only changed the racors one time and it was not even necessary. This was 700 gallons of fuel, (boat held 1050). Offroad diesel is a poorer quality then it was 5 years ago and before, back then the only time you had algae issues was if the boat sat 2 years or more. Low sulfer diesel will nearly dissintigrate the algae, next time you empty your racors, pour it in and you'll see it dislodge all of the algae in there as well.

Also, you rarely see water in diesel fuel because that is what the algae grows on. It needs heat, air, and water in order to survive. So basically the algae eats the water.

Chances are your boat has an additional fuel tank that you are not using to make up the 480 gallons. Ocean likes to do this a lot. It usually has another fuel fill, generally foward somewhere and this tank is situated higher then your normal fuel tanks and has a valve and just gravity feeds in the main tanks. It sounds like you simply ran out of fuel. 6-92's at cruise generally burn around 40 gph (both engines at cruise), so for a 4 hour trip you would've burned 160 gallons.

Hello,

I wasn't being a scare monger, just realistic. I've captained yachts professionally for the past 15 years, in various parts of the world and in my experience whenever I followed the regimen I suggested, I never had fuel problems.

That's why I started (company name) , because I use the products that I sell.

Sooner or later any diesel powered yacht will have fuel problems. It's not a matter of "if", just "when". The better you are at preventative maintenance of the fuel system, the less chance you will have that problem when you least want it; i.e., heavy seas and rough weather.

Cheers.

Dear Jeff,

Have you NOT noticed our rules, posted at the top of every forum about self promotion and commercial posts? I'm betting you have, but decided to test your luck anyway! Your link has been removed. Your membership is next.

Sorry, had not read the rules. My apologies.