Vetus M4.14

Jmc1764

Jmc1764

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Hi, I have a vetus M4.14 (Mitsubishi K4) it is quite old believed to have been fitted in the early nineties. In the survey report for the boat done 2001 it comments on the engine running up to 2800 rpm in drive as normal. However now she only runs up to 2100 rpm at full throttle in drive. She also cranks for a while before the first start of the day, usually 20 seconds before starting. once the first run is done she starts on the button all day long. I have given it a good service,replaced glow plugs, changed all oils and fuel filters including those before the engine. It runs very smoothly and quietly at full throttle but I just wonder is it giving full power and what could be the reason for not making 2800rpm ? does anyone else have one of these engines, what issues have you had to overcome ?
 
My M3.10 (3 cylinder version) had similar symptoms. Needed a head overhaul (valves and seats were shot in 2 of the 3 cylinders) and injectors serviced. I would also check the exhaust passages have not coked up.

KR
Yoda
 
Hi, Whilst underway. To be fair the engine moves the boat along reasonably well, it reaches 5-6 knots which I guess is not bad for 4.5 tons and 34 ft long ? If I had not read this old survey I would have assumed that the 2100rpm was normal ? I just wondered if it could be a fuel or injection pump issue as it does not start on the button from cold. The engine is old but has only done 1040 hours.
 
Dont know this engine but check engine revs in neutral and check with manufacturers specs.
Should be 3600 revs in neutral.
 
Last edited:
Wrong prop? When I changed mine I went from labouring at lowish revs to flying along at full revs. 6.5kt as against 7.8kt with the new propeller.
 
Ps. I have an M3.10 in the other boat. It takes a few turns to start, too, but then is fine for the rest of the day. Perhaps most older engines are like that?
 
Hi, yes I tried it in neutral, she will freely rev up to 3600rpm with no load. The propeller is a maxprop feathering type. it has been on since the engine was fitted as far as I can see. all the paper work tallies up to the same time. I think the exhaust may be worth checking and maybe the tappet clearance ? other than that I can't think what else to check.
 
Hi Petek , there is no air filter only a muffler that actually does not muffle much, I did want to fit some sort of air filter but there is not much room to get anything in there. Has anyone else got an air filter on a Vetus ? do you have a picture of what it looks like ?
 
Do you have a clean bottom? If the boat has not been out for a while the weed can cause significant drag and that means the boat wont get to full speed. Does the engine smoke when you give it full throttle but it only gets up to 2/3s max revs?
 
Hi, there is a kind of slimy fur on the bottom, I was hoping a few hours down the river would help wash it off, maybe its time to get that jet washed off ? The engine does not smoke at all, burns very clean and no unpleasant smells. I have taken off the flexible exhaust and put a camera up the bend and it looks quite clean in there, I can see the holes in the heat exchanger are clear and the pipe bit up to the manifold is not crusted or sooted, just a light covering of grey /black soot, it pumps plenty of water out the back when running.
 
That sounds like some sort of fuel starvation/shortage if it runs clean but just wont deliver full power. Is the throttle cable correctly adusted so that it actually fully opens? Any chance of partial obstruction in the fuel lines or tank take up. You say you changed the fuel filter. Correct one fitted correctly and not too restrictive? Was it all OK before you serviced it.
 
Jmc1764 said:
Hi Petek , there is no air filter only a muffler that actually does not muffle much, I did want to fit some sort of air filter but there is not much room to get anything in there. Has anyone else got an air filter on a Vetus ? do you have a picture of what it looks like ?
Click to expand...
The plastic box on the same side as the fuel pump is the 'air filter' but doesn't seem to actually have a filter.

Yoda
 
The condition of the engine is best assessed with a compression test on each cylinder. A workshop manual should give you the as new readings. It is relatively easy to do. If you find this OK then check fuel supply is not impeded and clean and the injectors are in good condition. My guess is that with low hours on an old engine you may find piston rings worn and bores glazed in which case hone the bores and fit new rings. Common to find bores are not worn but rings are if the engine has been run at low load..... No point in speculating though. Do a compression test and see if it is down first.
 
UPDATE: So after going over everything, mostly suggestions from chaps here I am getting closer to the problem, or as it happens a whole list of issues that add up to the poor performance. So starting has been improved by changing all the filter in the fuel line, the RACOR had some pinky wax clogging it up. I assume it was from some cold weather some time ago waxing the diesel. It now starts pretty good from cold. Also it revs up better. The exhaust elbow was very crappy, its a cast iron effort and was partially blocked with huge chunks of rust. This has been cleared out and then the paint popped off relvealing a large hole ! New part on order, temp repair made with titanium putty. Next the propeller: took the booat to the hard for a bottom scrub and found some fishing net tangled on the prop, its a MAXPROP feathering thing, this netting and debris was preventing the prop taking its correct position so it was actually changing direction to forward and reverse but not going fully so this was creating a bad angle and lots of resistance. After all that it now runs upto just over 3000rpm under full throttle and hits 6.5Knt. Just need to change that exhaust elbow when the new one arrives. There was also a lot of weed and unidentified new life forms hanging on the bottom of the hull, luckily it was easy to wash and scrape off to reveal a clean and slippery bottom !
 
I have the same engine and I found out that throttle was limited to 2000 revs by a piece of wire around the throttle lever next to the engine. After I have overhauled the engine it now reaches 2700 revs. However at this revs range the engine started overheating . We changed the seawater cooling pump to a bigger one used on bigger engines. However the problem stay there and now I've noticed that any revs above 2000 the coolant starts bubbling up. Can anyone please help me and let me know what is the psi pressure of the cooler cap? Yes I have tried fitting motor vehicle ones since I cannot get hold of the original vetus spare.
My mechanic is insisting that the cooler is undersized for the engine and that the rev limiter was set to 2000 for a reason.. I cannot believe it as why would vetus sdrsign cooler on an engine that can rev up to 3000... Anyone can give me suggestions or ideas?
 
Jmc1764 said:
UPDATE: .......... Next the propeller: took the booat to the hard for a bottom scrub and found some fishing net tangled on the prop, its a MAXPROP feathering thing, this netting and debris was preventing the prop taking its correct position so it was actually changing direction to forward and reverse but not going fully so this was creating a bad angle and lots of resistance. After all that it now runs upto just over 3000rpm under full throttle and hits 6.5Knt. Just need to change that exhaust elbow when the new one arrives. There was also a lot of weed and unidentified new life forms hanging on the bottom of the hull, luckily it was easy to wash and scrape off to reveal a clean and slippery bottom !
Click to expand...

I'm with Biggles in #13 on this one. In 2007 I sat in Syracuse, Sicily, for a few weeks. When I lifted the dinghy it was encrusted with shells. On the flat calm trip to Malta, couldn't get more than 2000 revs, and 4 knots, out of the boat where, previously, 3000 revs and 6 knots was straightforward.

When it was next lifted, the bottom was covered in the same shells as the dinghy had been.

No bad thing to do the other stuff, but my educated guess is that drag and the prop are the cause.
 
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