Yanmar 2GM Won't Start After Winter Layup

[zippy]

My Yanmar 2GM will not run after my spring launch. If I fully open the throttle, the engine will catch and chug along at low RMP and put out huge amounts of black smoke. It can chug for 2 or 3 minutes this way before stalling out. At one pont is started to speed up but then died down again and stalled. Any movement of the throttle from wide open and it stalls. I have had it chugging along about 6 times but it still won't speed up and always stalls. There seems to be lots of fuel expelled at any of the bleed scews I open up, air filter is fine. Could the fuel volume be a problem even if the bleeding screws put uout fuel?

Any ideas?

[Mark1977]

I had the same problem with my Volvo penta last year turned out it was only firing up on one cylinder. The decompression valve was stuck. I'm no mechanic but thats what happened to mine. I sure someone else will chime in with some other options.

[delmarrey]

Not knowing how many hours on the motor, I would guess that the injectors are sticking open. If there was any water in your fuel it could have rusted the injectors


A few questions;
Are your injectors due for maintenance? (ever 1000 hours)
Are you in a cold wet climate?
Do you put any fuel additives in your tank?
Does you prop shaft turn free in neutral?

[zippy]

************************************************** *
A few questions;
Are your injectors due for maintenance? (ever 1000 hours)
Are you in a cold wet climate?
Do you put any fuel additives in your tank?
Does you prop shaft turn free in neutral?
************************************************** **
A few answers
- Engine is due for maintenance, don't know the hours but it is a 1984 model with no overhauls.
- Climate is cold, wet, eastern Canada.
- I don't usually use any fuel additives, although I have added winter stabilizer.
- Prop shaft runs free in neutral

[delmarrey]

If the oil level is too high it could cause smoking. If that's the case check for presents of water or diesel fuel in the oil. If so, then there could be several other problems.

If it were mine I'd replace the fuel filter checking for any presents of water. As well, I'd check the fuel tank to see whats on the bottom looking for water and/or crud.

Also. I'd pull the injectors and get them checked out. The only other thing that would cause the black smoke would be if the motor were over loaded, like if the tranny or crank shaft were seizing up.

[S/V Antares]

A carboned up exhaust elbow could cause black smoke. Delaminated exhaust hose also. I bet it is the injectors. Pull them out and rehook them up ouside the engine. Rotate the engine and see if the injectors dribble or spit a fine spray.

[GordMay]

Flooded exhaust?

[delmarrey]

Originally Posted by GordMay

Flooded exhaust?

Here in the PNW we do have problems with swallow nest's in exhaust outlets but usually get blown out in a short while.

[zippy]

Post Mortem:

I cleaned out the engine side fuel filter (looked fine) and fed from a diesel gas can to bypass my fuel tank and racor. I then put the throttle on full, it started right up but would still only run at 1200 rpm with lots of black/brown smoke. After a few minutes I tried bringing the throttle back to 1/2 ( before that it would only run at full and died when I tried to throttle back) at which time the engine sped up to normal. After a few more minutes I was able to run at full throttle with very little smoke and all seemed back to normal.

I am putting this down as a fuel problem. Possibly water that got by the racor?? I opened my fuel tank and pumped some fuel out from the bottom but didn't see any sludge. There may have been a bit of water. The racor bowl did not appear too bad either. The only way I got the engine to start at all was by having the throttle wide open but clearly it did not want to run in that position.

Now I noticed a small leak in my exhaust elbow, but thats a whole new problem

[captain58sailin]

Replace the racor filter if you haven't done so, drain the filter housing, I would change the secondary filter and clean out the housing as well. That is something I do every fall as a part of the preparing for winter storage process, I also use fuel additives like Power Service and Active X to kill the algae.

[westsail42]

I just went through a similar experience with my Yanmar 3GM. My suggestions.

1. Is it cold where you are? My Yanmar is a tough start when cold and has been sitting for a long time. Turning a space heater on it overnight causes it to fire right up in the morning.
2. Did you bleed the fuel system? If so, re-recheck it. There may be an air leak somewhere.
3. pull the injectors and have them checked. After 900 hours, mine were stuck open.

Ultimately 2 the cause for me. The racor filter was getting clogged up enough that the fuel vacuum was increasing when running to the point of opening an air leak somewhere. Tightening fuel hose clamps and the racor filter lid solved the problem. I still need to get in there and replace the filter cartridge.

[Bash]

Consider it a message from the diesel gods that you're due for injector maintenance.

[S/V Antares]

It starts.... so the fuel system works good enough. Take the hose off the elbow and check for carbon. Leave the hose off and use a large wet dry vac to see how much flow you get by sucking on the overboard exhaust. It you have a bad hose the vac will pull hard. If ok it will run no effort. Ya have to have air in and out to make power/rpm The black smoke says there is enough fuel. It is Exhaust or injectors.

[S/V Antares]

Great to hear it runs! Will it make desired rpm in gear?

[delmarrey]

At first it was burning up the fuel still in the system.
It appears you have bad fuel. I'd pump out the old stuff and fill with new and change all filters. Then run it in gear at the dock & if OK, take it out for sea trial.

Cold weather is not friendly to diesel fuels, it tends to separate especially if it has any boidiesel in it.