Yanmar 2qm20 not starting troubleshooting

[jimbunyard]

Originally Posted by Americanrancher

HAUL THE BOAT OUT OF THE WATER!

Or you could try, after verifing your bilge pump is in good order, adjusting the tension between the fore and aft glands by loosening the two clamps on the forward gland and sliding it whichever way stops the leak.

While you're at it check and see if either face is damaged or dirty. If worse comes to worse you can always slide the forward gland forward enough to pack something in the shaft log around the shaft until you can work out a plan of action,

A lot can be said for the old standard flax stuffing box, especially if you replace the old style flax packing with teflon packing...

[barryglewis]

Wotname,
how much ATM per litre of diesel for injector cleaning?
Thanks

[Icarus]

Seems to me after 4 years of the engine not being used I certainly would remove the injectors and get them seviced. Especially you experiencing fuel related problems.

Did you check the engine oil if its contaminated with water?
You could have a blown head gasket.

Compression check?
Good luck

[Wotname]

Originally Posted by barryglewis

Wotname,
how much ATM per litre of diesel for injector cleaning?
Thanks

Usual disclaimer - I'm not a diesel mechanic etc etc.

I am only relating to what has worked for me for older simple small diesel engines (i.e. <50 hp, old school injectors etc).

I use 5% ATF i.e. 50ml ATF per litre of diesel and for say 2 to 10 hours.

I have used proprietary injector cleaner additives and to be honest I can't say that they were any better and perhaps not as good.

But then again, I'm happy to pull apart old injectors and clean them myself. Of course I can't pop test them properly but I just follow the methods outlined in old Yanmar manuals for field testing and that is good enough to know if nozzles are working well enough to be serviceable.

[jimbunyard]

Attention newcomers! The engine is running, and sounds pretty good.

https://www.youtube.com/watch?v=1e8O...ature=youtu.be

No need for compression tests or pulling injectors or changing cooling or exhaust systems; if he gets his alternator and shaft seal problems sorted looks like he can tool around as soon as the authorities loosen the pandemic restrictions...

[Dalestr]

The shaft gland must be dealt with. Hope you have two electric pumps and a means to plug the gland if needed. To work on that while boat in the water, I'd want the possibility of a quick hauling out to dry dock. If you can swim under you can try jamming polyethylene foam between shaft and shaft tube to reduce leakage while working on it. Barnacles are very dangerous though. It may just require realignment of the inner boot which acts as also a spring for the face-to-face seal. I think that gland is a Brit or Aussie design. It looks similar to this:https://rlmarine.com.au/manecraft-seals/

If you want to know if the fuel in the tank has biological growth after sitting so long. You can use a small hand pump (like those used to suck out engine lube oil) rigged to a long copper tube and suck fuel from the bottom of the tank to a jug to see if there is a bottom layer of water or crud. Algae grows at the water/fuel interface.

Your engine appears quite viable and probably does not need a fuel lift pump right now. Your engine valves may have some spot corrosion or a stuck piston ring that could clear itself but you may want to seek a compression test or the injectors tested if the engine is reduced in power. I don't think you have had a chance to really load the engine yet to learn this. I'd prefer to see the fuel return going back to the tank as is normal.
It appears your earlier starting problems were due to air getting into the low pressure fuel system from air leakage at mainly hose joints. Replacing the rubber fuel lines may be wise.
Note that manual operation of the fuel pump requires travel the pump's actuator arm that rides on the cam and if the arm is at the highest point of the cam (round eccentric) then you cannot pump fuel manually until you rotate the crankshaft 180 degrees or more (release compression). The small lever travels at least ~10mm before it contacts the pump actuator arm.
Your earlier video shows limited exhaust water volume but raw water cooled engines need less water but I'd check the pump impeller. The thermostat is maybe recycling most of the water until the engine warms up but after years in one position, some of the impeller blades may have a fixed curved shape. They should be nearly straight when the impeller is removed. Watch for overheating when the engine is under load.
The alternator is trying to put out amps but the belt is too loose and screeching. You can remove the belt and see if it spins freely and quietly.

[WestcoastCrown]

thesauvage, glad to see it is running. Seems the problem was the dreaded 2QM air leak, they can stop these engines from ever starting.

In my earlier posts I should have mentioned that the thermostat should be replaced as soon as possible. If the engine has been sitting for sometime the salt water accumulates in the exhaust manifold, if it hasn't been drained. This will result in corrosion of the thermostat.
The engine will sit and idle for some time and then overheat when under load. if its not too bad, the thermostat can be taken apart, cleaned with a wire brush and reassembled. if it is too far gone, a new one will be required.

Earlier posts regarding replacing the anodes and other standard maintenance items are great advice.

Good luck with the rest of the issues, seems you are well on your way.

[barryglewis]

@Wotname,
Thanks.
Appologies for thread drift

[Pat_D]

Change out the fuel. I just got over a similar issue. No crud or water in the filter, but when I supplied fuel from a gerry can it would run (with enough bleeding/spinning to get past the tank fuel). Then not run from the tank.
As soon as I drained and refilled the tank my problems were over.
Btw, installing a squeeze bulb before the filter helped in bleeding but mostly really convinced me I did not have a pickup tube etc. problem.

[Pat_D]

Dunderhead me. I looked for but missed the additional pages link . ...running is solved. But, while I see lots of recommendations for electric fuel pumps, an outboard style squeeze bulb really works for me- easy to pump lots of fuel, cheap, easy to install, and the advantage of feeling that the feed is good (it will get spongy or collapse if not).
My two cents, and what a great group of pros on here.

[Cheechako]

FYI, I see "shaft seal needs work" noted. Beware that often a shaft that has sat for years will be heavily corroded inside the packing gland. This is due to the low oxygen environment in there when it's not used that long which attacks stainless steel. The only solution is to replace the shaft.
Hopefully that is not your case...

[thesauvage]

Hey guys,

sorry for the late reply & thanks again for all the very helpful comments and suggestions.
As I've said, the engine is running again, it's starting without any hassle every time now. :-)

The problem in my case was simply, that all fuel hoses had been mounted too loose, so the engine could not bee bleed throughly.

The issue with the Dripless shaft seal :-) Haha guess what I didn't haul the boat...
I googled around a lot beforehand, and found at least some examples of people that exchanged their shaft seal while still IN the water.

I took some photos for reference:

https://imgur.com/gallery/wyi0et0

It actually was quite easy, but getting all stuff sorted out and have everything on hand is crucial :-) Also very important to have your shaft and shaft tube diameter measured VERY exactly!

Steps I took:

1.) Unmount the shaft coupling from the gear box.

2.) Loosen the shaft hose clamp of the old seal, so I could slide out the shaft further. (I did this until the prop touched my rudder) A slight amount of water to entered, but not even enough for the bilge pump to kick in.

3.) I was lucky that my shaft coupling was a split-style, the ones that simply clamp to the shaft (see photo) And so it was quite easy to remove :-) The locking screw (Allen key) was so rusted, that it broke when I first attempted to unscrew, but could pull her with a bolt pulling tool.

4.) I got all the new shaft seal parts in place (PSS dripless shaft seal) and also arranged all tools I might need for the process, to be easily and quick to reach.

5.) I loosened up all hose clamps, that secured the old seal to the hull and the shaft. Then pulled the seal off its hull mount (towards the engine) and off the shaft.

6.) The amount of water gushing in now was FRIGHTENING :-) Bilge pump kicked in immediately. I wrapped an old towel around the shaft and pushed it towards the hole, to minimize the water influx. (I have a very deep bilge, but it filled up about 1/2 in no time, the pump wasn't able to keep up)

7.) With one hand holding the towel in place, I took the rubber part of the PSS seal and put it in place on the shaft, same with the SS ring that is supposed to sit on the shaft and to push on the rubber part.

8.) I released the towel and quickly pushed the rubber part in place, then compressed it against the hull with the SS ring.

9.) Step by step I pulled the shaft inside the hull again, reattached the coupling to the gear box... Done! :-)

I poured two fingers rum extra... but I did it.

[thesauvage]

The PSS Seal works excellent btw. I've tested it both in Fwd and Rev gear with max RPM and could hardly spot a single drop from the seal.

[thesauvage]

I tested the alternator with the help of a multimeter, and I get a very mixed output in the range of 0.3 - 1.6V with engine running at idle speed.

Videos I've seen on YouTube videos that say it should at least show around 13.6V at least... Guess means it is broken :-(

What kind of replacement alternators are out there, that are compatible with my Yanmar 2QM20 engine?

[a64pilot]

I would take my alternator to an automotive electrical shop, they are getting a little rare, but many are still out there, most probably you can have yours rebuilt for a fraction of new cost, and it’s been my experience that a good overhaul is often better than a Chinese new alternator, often times a good overhaul shop will buy better quality bearings etc than are used in the new ones.
The shop should first test your alternator, it may be that your problem is elsewhere and them testing it for you could save you some money.