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1999 Beneteau 50
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Discussion Starter #1
We just had our injectors re-built and I'm getting ready to re-install them on our 4JHE. I have not been able to find the specs in the manual.... should I just snug them down? Having them rebuilt was not cheap, so I don't want to guess.

The injectors are held in place by a metal hold-down with two holes for studs that pass through. There are two nuts that you tighten down on.

Thanks
 

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I'm guessing that is the same as my 4JH2E which also uses a metal retainer with two studs. My manual quotes 4-4.5 kg-m (28.9-32.5 ft-ib)
 

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Do you have a new "crush washer" for each injector? Each time this was done on our former diesel, this was required. Not particularly expensive, but they are a single use item.
 

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1999 Beneteau 50
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Discussion Starter #5
That sounds like the spec for the nozzle nut... isn't that different from the two hold-down nuts?
 

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That sounds like the spec for the nozzle nut... isn't that different from the two hold-down nuts?
OOOOOOOPS!!

You sir, are quite correct...
Nozzle Nut Tightening Torque 4.0-4.5 kg m ( 28.9-32.5 ft lbs)
Nozzle Retainer Tightening Torque 2.0-3.0 kg m ( 14.5-21.7 ft lbs)

My apologies to the OP. If I remember correctly, they are 10mm, so with steel studs and nuts in a cast iron head, and holding a steel retainer which bottoms against the head, probably just fine.

Now, I wonder which number I used when I reassembled my cylinder head.
 

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1999 Beneteau 50
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Discussion Starter #7 (Edited)
No worries; I ended up using different specs but now I have a new problem; the engine doesn't rev past about 1400 RPM when in gear. When out of gear, it seems to rev up fine. I'm researching to see if this is a common problem. My gut says it's not getting enough fuel. Come to think of it, our diesel heater has been frequently losing its prime; it draws fuel from the Racor.

My last resort is to call my father-in-law. He's a tugboat mechanic.
 

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Your gut is correct. When throttling up and requesting more torque, the engine responds by injecting more fuel. When was the last time you replaced the Racor? Do you have a lift pump between the fuel tank and fuel filter?
 

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1999 Beneteau 50
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Discussion Starter #9
I replaced both filters about a month ago. We do have a lift pump. I'm starting to think that the in-tank strainer is the culprit; it's the only thing in common between the engine and the heater system. Over the winter, we ran the tank pretty low using the furnace, so it might have been exposed to air and gotten gummed up. I just topped off the tank so I'm hoping there is an easy way to lift it out of the tank.
 

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If you suspect the feed from the tank may be partly blocked, a quick check would be to feed the engine from another source. If your Catalina 42 is the same a mine, you have a small inspection door just inside the starboard aft cabin. A can of diesel secured on the cabin floor and a feed line would enable you to test the entire fuel system from the engine mounted filter on. Maybe just disconnect the line from your Racor and drop the end into the can. One good thing about Yanmars is how easy they are to bleed.
 

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Discussion Starter #11
Well I opened up the inspection cover and the inside didn't look that bad, though the float had some green slime on it. The fuel pickup is on the opposite side of the tank and I don't know how one would be able to inspect it, much less clean it out.
 

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That green slime is algae, otherwise known as diesel sludge. It grows in diesel fuel when it has been contaminated by water (it takes just a tiny amount of water). It can block the fuel pump pick-up. Get a bottle of Stanadyne additive and add it to the tank. Then top it off completely with fuel.then run it for a while.
 

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Discussion Starter #13
So I bypassed the fuel tank and it still only revs up to 1400 RPM.

I then started the engine and loosened the flair nut to each injector, one at a time. There was no change in idle when I loosened the nut on the third injector. Some fuel came out when I loosened the nut.

So I suppose that means I have a bad injector, which is a surprise because the shop tests them after being re-built. I will probably call the shop in the morning but to rule-out the pump, I should probably swap two of the injectors and see what happens.
 

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Discussion Starter #14
So I swapped the # 2 and 3 injectors and when I re-did the test from my last post, cyllinder 3 still doesn't fire. There is definitely fuel getting to the injector; I could tell when I cracked the nut.

I guess that leaves the pump? That makes no sense. It worked fine before I pulled the injectors the first time.

Running out of ideas.
 

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Discussion Starter #16
I found the problem but now the original problem is back.

When I removed the injectors, I tried disconnecting the # 3 injector line from the pump. The flare nut threads onto a sleeve that threads into the body of the pump. When I tried to loosen the flare nut, it wouldn't break free from the sleeve; instead, it backed the sleeve off by about 1/16th of a turn. I had forgotten. I tightened it back up and tightened the clamp that holds the sleeve in place. Based on the diagram, there's a lot of little pieces held in place by that sleeve, so it's sensitive to small movements. I started it up and it idles faster and revs up under load.

However, when I rev it up, there's once again quite a bit of smoke coming out the exhaust. It's definitely un-burnt fuel. So it seems like having the injectors rebuilt didn't cure the problem.
 

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Discussion Starter #17
We took the boat out yesterday for the first time since my last post. Initially there was smoke coming from the exhaust but it went away after about five minutes, I suppose because the engine reached operating temperature. The smell of the smoke was different this time; it smelled more like burnt oil than unburnt fuel.

For now, the problem seems to have went away so perhaps it was the injectors. This exercise taught me how touchy (though reliable) mechanical fuel injection can be. It might be worth while to have the injector timing checked and for that matter, check valve clearances.
 

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Discussion Starter #19
I think you're right about the residue. It could have been un-burnt oil that got past the piston into the combustion chamber.

My father-in-law, (a tug mechanic), thinks that I probably had an internal leak inside the injector pump for that cylinder. It was probably caused by the sleeve not being fully seated into the pump body.
 
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