Black smoke on yanmar diesel

[skatun]

I have black smoke coming out of my yanmar 2gm20, to the story its to be said that the engine were not started for 15 months.

What I have done so far is:

1. Changed oil and oil filter
2. All diesel hoses and filters
3. All water hoses are new
4. Removed exhaust pipe and looked into the engine seems ok
5. New antifouling, sinc anodes, saildrive gear oil change
6. Renewed starter and alternator
7. Changed vbelts
8. Changed the bleed pump
9. Tested opening pressure of injectors to ca. 145 bar open at the same time
10. Run the injector pump without injectors attached, seems ok
11. Adjusted valve clearance
12. Removed air filter, waiting for new one

So what should I do next? It seems to not be running on maximum rpm and also have problems running on idle in gear. My RPM does not work, seems to be the tachsensor(took it out no change in resistance when holding a spanner close to it) but I can not find a new sensor, any ideas where to get one? So I can unfortunately tell the RPM speeds.

1. So could it be the governor?
2. How to check this?
3. Should I lift the top off and check pistons?
4. Should I do a compression test?

[hobopacket]

Compression test would tell you a lot. Black smoke is often oil being burned. Maybe valves are out of whack or piston rings.

[skatun]

Originally Posted by hobopacket

Maybe valves are out of whack

How to test and change this?

[StuM]

Originally Posted by skatun

How to test and change this?

Like he said. Compression test for a start.

[GordMay]

Greetings and welcome aboard the CF, skatun.

[hobopacket]

A compression test will narrow it down to either of those two things. If compression is low. Time to start tearing off the head and see what you find.

[tjandoverguy]

i had the same engine ran fine with no load than smoke ,oil ,fuel lays on the water
pulled head,# 1 piston wasn't coming to the top, bent connecting rod, engine out yesterday in stt,

before pulling head

new exhaust manifold, mixing elbow
rebuilt injectors, and pump
new fuel pump

3gm30

[TheOffice]

Is it smoking at all speeds or only when above 2500 rpm? That is a dirty bottom/running gear, not a bad engine.

[skatun]

Originally Posted by TheOffice

Is it smoking at all speeds or only when above 2500 rpm? That is a dirty bottom/running gear, not a bad engine.

Well i do not have an rpm measurement(broken see first topic) so its hard to say exact what RPM smoke start at, bottom/gear were done less than a month ago, so its all super smooth..

[skatun]

Originally Posted by hobopacket

A compression test will narrow it down to either of those two things. If compression is low. Time to start tearing off the head and see what you find.

What should the compression pressure be?

[skatun]

The valve clearence should be 0.2mm right? In the maintaince manual it say that black smoke means wrong valve clearance.

[ub1]

Check prop if in the water.

[lesterbutch]

I think what you need is a mechanic! Remember where you might be when it breaks down! It takes a lot longer to get your tow than on land! Might also check your tow insurance make sure it's adequate and current!
Recently towed! Without insurance it would have cost over 3 thousand dollars!

[AndyEss]

Black smoke in heavy truck diesels often indicates bad injectors. You checking the injector cracking pressure was a good move, but the spray pattern may be bad and of too much volume (too rich causing the black smoke which is mostly unburnt fuel) because the valve seat or stem head is worn out and the metering is off. Cracking pressure should only indicate that the injector spring is still within spec and the seat is still good enough to seal properly when fuel pressure is below the cracking (valve opening) pressure. It doesn't necessarily say anything about correct fuel metering.

[boatman1]

What Lester says