Sick of our 4108 Perkins need suggestions

[billknny]

As many people have already said, the chances are really very, very low this problem is with your engine. Rather it is somewhere between the engine and the fuel tank.

One way to help diagnose this kind of problem is to use a short piece of clear tubing and install it (only temporary while you are watching!) into the fuel line and look for bubbles. If you see bubbles on the outlet of the fuel filter, then put it in the inlet of the fuel filter, and keep going back until you get clear fuel flow.

As has been mentioned, the internals of the fuel tank are also suspect in this problem. It would really, really suck to change the engine and have the problem continue.

These problems can be tough to track down, they can be situational (like nearly empty fuel tank!)

If you cannot figure it out, I would suggest replacing the ENTIRE fuel feed system. From the dip tube in the fuel tank, to the lift pump. ALL of it. Every hose, every piece of tubing. Every fitting. You would (I hope!) do that as part of a new engine installation anyway, so if you DO repower it is not money lost.

[jewt]

The 4-108 was a great engine but is now a bit long in the tooth and , at least here in the states, almost impossible to find parts for.
I repower a couple of years ago with a BETA-43 and have been very happy with the lack of oil leaks, the ease of bleeding the engine when required, etc.

If I had it to do over however I would keep the Velvet Drive transmission. Unlike the Twin disk with a cast aluminum case that was the primary option with the 43, will actually break the case if the rpms are too high during a shift.

The VD is bulletproof.

jewt

S/V Bifrost(now # 8)

[Stu Jackson]

Originally Posted by atoll

i had a problem like this once,it turned out to be the bleed screw thread on the body of the primary fuel filter on the engine .threads were worn and bleed screw allowed air in.
replaced the body housing and no more problems

I had this issue years ago, when I stupidly loosened that screw unnecessarily it turns out.



You have received tons of good ideas here. Another one: a friend reported the check valve inside his filter housing got stuck. I didn't even know there was one!


All sorts of things to easily check before you go to the big show.


Good luck.


ITWMB, I'd make a checklist of all the good things in this thread and have at it. Should take you all of maybe a day.

[Lserpa]

Originally Posted by JulianGullsway

For those of you who have read some of our previous posts you may well under stand. Ever since we’ve owned Gullsway we have always had the same nagging problem of air getting into the system and making the engine cut out, we have now after quitting work and sailing to the med over a 2 year period had to return to the UK to work and normal life, we now get about 4 week’s sailing a year as she is still in the med so time is precious aboard but the same problem persists during our trip she will run solid for 24 hours with no problem then die we would change filters re bleed and the same would happen then out of the blue it would happen and die often in the worst possible times and to be fair every time we leave port the constant nagging haunts us will it or won’t it die today we have listed a few things to eradicate the problem; new lift pump, refurbished injectors, this week had the fuel injection pump refurbished ( this week as we tried to get to Sardinia) all new copper pipe work every nut and bolt copper washer checked and double checked, additive added to fuel and inspection hatch in the tank checked prior to every journey. To be fair we’re about sick of it....... any recommendations for a re power......sorry for ranting but weve had 2half week’s off work and been launched then re hauled today after having just one night at anchor and decided to just fly home early

Once I had a problem with a Yanmar: it would work perfectly except when wind went up. It stopped at the entrance of Sete harbour and I almost lost the boat in Tanger due to the engine failing. In between it worked like a charm. It turned out a fuel hose had an angle and closed when the boat healed.

We replaced that hose with a copper pipe and problem disappeared.

[sainted]

Not the same kind of problem, but illustrates the vagaries of diesel fuel systems. After I rebuilt my Yanmar about every fourth attempt to start, it wouldn't. I'd have to bleed the fuel system, then it would start and run fine until I shut it down. I finally noticed a little bit of fuel pooling on the head. Turns out that one of the injector to fuel line connections (it's a flare fitting) was leaking a tiny bit. When the engine shut down with the injector pump piston for that cylinder in just the right spot, the system would suck air thru the fitting. Fixed the connection and not a problem since.

[boeing1]

I also had a engine that had the pickup tube clogged, this would be a good starting point, then check fuel lines, clamps ect. to engine. replace as needed, good point on NOT reusing the copper crush washers

[jharding]

a lot of problems come from a dirty fuel tank, I had many problems like these listed, once I mechanically cleaned fuel tank, filters stay clean pickup tubes don't clog, I've had no problems since. I couldn't believe how much junk came out of my fuel tank. 1984 boat and probably never cleaned. Getting fuel polished does not clean the tank!! It was never a problem in calm water, once in rough seas everything got stirred up and clogged things up and sucked air. Always at the worst place and time.

[Cadence]

Originally Posted by a64pilot

If air is getting into the fuel system, it’s very, very unlikely an engine problem.
Imagine how sick you would be after paying for a repower, to have the problem reoccur

Yep, air can sneak in where fuel can't sneak out. It sounds like every fitting should be revisited on the supply side.

[Scout 30]

An easy way to find fuel leaks is to place an electric fuel pump first in line after the tank. This will pressurize the line & anywhere that it was sucking air will now drip diesel. This also makes it easy to prime your filters and will serve as an auxiliary fuel pump if the primary goes bad..

[Lepke]

It's a pick up tube or fuel line problem. Not the engine.

Big engines don't have screens on their tubes or have an easy to remove tube. Screening tank contaminants is the primary filters job. Using a fuel conditioner, especially in tanks where diesel is more than a few moths old, is a necessity for clean tanks.

A quick fix on fuel line air leaks is to coat the fitting with a rubberized paint, also available in spray cans. If it works, you can run a new fuel line. Also if you have the old style secondary fuel filter using a cartridge instead of spin on, they can leak.


I have a 1972 4108 running a generator. I have no problem getting parts.

[roland stockham]

With the original fuel system I had similar problems, lots of people seem to have had this. In my case I think it was sucking air through the filter. I have since fitted a day tank which completely solved the problem. Now if there is any leek in the line fuel drips out which makes it obvious. Also less likely for fuel to get in. A small day tank fitted to gravity feed the engine may cure it. If you don't like that idea or there is nowhere above the engine to fit it try adding an electric fuel pump. Give 2-6psi pressure in the fuel lines so again you see a leak. This seems to be especially a problem if there is a significant lift between the tank and the filter. I once had a mechanic described it a the fuel being 'stretched' because the lift pump is at the engine end of the line and is sucking not pumping.

[Minggat]

While I feel for your frustration, please note that not too much support for a repower. You might get different results with a repower, but that might be simply because the fuel system hasn’t been cracked open. Better to discover what is breaking your heart tham blame it on the whole engine. An engine that has served so many others so well.

I had an old gasket stuck in my primary filter for years that caused me grief. The joy I got when I found that was great. If I had paid thousands and solved the problem, my joy would not have been so great. Bottom line is, sorry... but you’re missing some point in your fuel system. We’re all voting that you find it before you repower.

[Minggat]

Originally Posted by jewt

The 4-108 was a great engine but is now a bit long in the tooth and , at least here in the states, almost impossible to find parts for.


S/V Bifrost(now # 8)

I thought so too. Past tense. There are good sources. I’ve been using British Marine in San Francisco.

To the OP. I reread your post and others looking to see if you had added an electric fuel pump to your system. Very cheap and it covers a multitude of sins. It may help expose your problem, but for sure it makes bleeding your system way easier. You can also configure your lines to give yourself a fuel polishing system.

Hope that helps.

[CarinaPDX]

I chased an air leak for the first couple of years and never found it; it only happened when I was drawing fuel from the keel tank under the engine. In such cases the lift pump has to create quite a vacuum in order to draw up the fuel as the level goes down, and this vacuum drew in air somewhere that otherwise wasn't a problem otherwise. The solution, as mentioned earlier, is to use a day tank. Now I use a vane pump to transfer fuel from the keel tank to the day tank. Problem solved.

When the time comes to replace the old Perkins I would suggest either a Yanmar or Volvo-Penta for world cruising, for the simple reason that there are dealers (with parts) almost anywhere you might cruise. In the US or EU only, I would buy a Beta. I used to have a Sabb diesel - the factory support was first rate but shipping parts into countries was a pain, often requiring an agent (and a lot of time and money). I have nothing but good things to say about the Beta engines but the lack of dealers and parts in distant places is a disadvantage.

Greg

[stormalong]

Originally Posted by CarinaPDX

When the time comes to replace the old Perkins I would suggest either a Yanmar or Volvo-Penta for world cruising, for the simple reason that there are dealers (with parts) almost anywhere you might cruise. In the US or EU only, I would buy a Beta. I used to have a Sabb diesel - the factory support was first rate but shipping parts into countries was a pain, often requiring an agent (and a lot of time and money). I have nothing but good things to say about the Beta engines but the lack of dealers and parts in distant places is a disadvantage.

Greg

I disagree with the Yanmar or Volvo-Penta recommendation. Both Yanmar and Volvo-Penta are marine specific engines and parts are pricey. Beta Marine engines are Kubota tractor engines and the parts are available worldwide, even in places where no marine services are available.



I replaced my 4-108 with a Beta 50 - the same block as the 43, just with a bigger bore. With about 4000 hours on it I am still happy with the choice.