Black Smoke Yanmar 2GM20

[GordMay]

This Link to Yanmar Help works
➥ Yanmar Marine Engine Help

URL: yanmarhelp.com/index.htm

[Therapy]

Originally Posted by mfeene01

I just went through the same thing with my 2GM20F. It took almost a year, a couple of sets of injectors and several mechanics until I found one who knew what he was doing.




Good luck.... MikeF

SHEESH!!!

[Badsanta]

Some one asked the right question. When was the last time the boat was hauled and the bottom and prop cleaned. I vote for exhaust elbow or fowled prop

[billmcc]

I sympathise - I have similar probs with a Yamnar1GM10. Will let you know how I eventually solve the problem. in the meantime see my posting "YANMAR 1GM10 SMOKEY NO POWER" for a list of the many efforts I have made so far. I am not going to let this beat me!!!!
Bill.

[turkish6]

We has a similar problem occur in last august but only when i was at max rpm. Black smoke with some black debris is water. power was fine. Did not use the boat for about month and seemed to get a little bit worse (smoked just below max rpm) and finally today at about half crusing speed it was smoking wit debris as usual. The boat was being hauled out today and once out of the water I could see that the prop was covered in barincales. Really badly covered... Could this be the cause of the smoking?

[Solitude]

Originally Posted by turkish6

We has a similar problem occur in last august but only when i was at max rpm. Black smoke with some black debris is water. power was fine. Did not use the boat for about month and seemed to get a little bit worse (smoked just below max rpm) and finally today at about half crusing speed it was smoking wit debris as usual. The boat was being hauled out today and once out of the water I could see that the prop was covered in barincales. Really badly covered... Could this be the cause of the smoking?

Yes !

[Chief Engineer]

I see this all the time in the Chesapeake in the summer.

My first question is when did you last have your bottom cleaned prop checked.

This situation is taken advantage of by bad "mechanics".

As my Port Engineer taught me many miles ago.....Look for the simple things first.

Originally Posted by turkish6

We has a similar problem occur in last august but only when i was at max rpm. Black smoke with some black debris is water. power was fine. Did not use the boat for about month and seemed to get a little bit worse (smoked just below max rpm) and finally today at about half crusing speed it was smoking wit debris as usual. The boat was being hauled out today and once out of the water I could see that the prop was covered in barincales. Really badly covered... Could this be the cause of the smoking?

[Bilgediver]

Originally Posted by Chief Engineer

The link to the Yanmar site is no good.

Can a bad cooling elbow cause black smoke decreased rpm under load?

Yes the elbow is the usual cause of black smoke on Yanmar engines as it cokes up and reduces the flow of exhaust gas so causing black smoke. I suspect all the OP needs to do is remove and clean the elbow and all will be back to normal with no need to rip of injectors or heads or fuel pumps.

[riptide]

Have inj. pump gone through-also fuel starvation will cause black smoke and loss of power-had it happen with a clogged filter

[tranquil star]

Just had the same problem with my yanmar 2GM 20 FCs , WOULD NOT REV OVER 2000RPM AND DRY BLACK SMOKE BY THE TON......................CHECK THE EXHAUST RISER/MIXING ELBOW IN THE FIRST PART OF THE EXHAUST BEFORE ANYTHING ELSE. My engine appeared to be pumping enough water out of the exhaust but on removal both exhaust mixing elbows were clogged 90%. A sure sign externally is if there are any cracks or even slight weeping from this part ,just replace it. Minards in Sydney have the best prices if your in Australia. Will post photos of these later.
Cheers
Pete

[wsvoboda]

I was just wondering where the location of the fuel tank to the fuel filters and down to the engine are? Is everything flowing down hill? I had problems with getting air locks because my fuel filter was above the fuel tank and could not get over 1500 RPM's after relocating the fuel filter below the fuel tank and just above the engine the problem went away.

[tranquil star]

Originally Posted by wsvoboda

I was just wondering where the location of the fuel tank to the fuel filters and down to the engine are? Is everything flowing down hill? I had problems with getting air locks because my fuel filter was above the fuel tank and could not get over 1500 RPM's after relocating the fuel filter below the fuel tank and just above the engine the problem went away.

On my catamaran the fuel tanks are built into the bottom of the hull and well below the engine some 15ft away but years ago the manual fuel pumps were replaced with electric ones. This cures many problems and makes bleeding the engine a breeze after filter changes, just turn on the ignition and the fuel is constantly fed.
I have fitted electic fuel pumps to all the boats I have had over the years and simply by passed the original engine driven ones.
Cheers
Pete
P.S.lOVE YOUR HAT,i HAVE THE SAME ONE A FRIEND BOUGHT BACK FROM THE STATES

[cfoxcvg]

Read my thread, may help help point you in a direction.

Yanmar 2gm20f - Black Water at 2700+ RPM

You will find that I ended up getting new shims for my injector pump and cleaning the bottom and running gear, I would not recommend you go to the shims yet. I only did because I knew I missed them up when I removed the pump and my the problem started right after that I reassembled everything.

If you haven't already I would verify the bottom is clean. Especially check the prop, once I only had 3 barnacles that were large and after removing them it made a huge difference.

[seafarer30]

Originally Posted by jmdezzutto

I’m at my wits end in working through a loss of power and “black” smoke issue with a Yanmar 2GM20 marine diesel on my 1996 Hunter 29.5. These symptoms suddenly showed up several weeks back. I suspected a dirty fuel tank and/or problems with the fuel. Drained the tank and then removed and cleaned the tank. Found debris in the supply tube elbow that restricted fuel flow. Replaced both the primary and secondary filters. Found little or no contamination in either. Returned the diesel fuel through a new West Marine water separator funnel. Bled the entire system. Final got enough pressure for the injectors and the engine started. I was able to idle, but still had an issue with power loss over 1700 rpm accompanied with black smoke. Decided to run Seafoam diesel treatment additive with a 1 to 1 mix via a bucket for several hours to clean the internals. This seemed to do the job. Ran engine through the entire range in neutral from idle to 3,200 rpm with no problems.

Took the boat out to test under load and ran between 1,500, and 3,000 for over an hour with no problem. I assumed all was well. Went out a couple of times and ran a total of 4-5 hours before the symptoms returned. Loss power and rpm’s at 2,200 rpm and the return of black smoke. Shut the engine down and sailed back to the slip.

Rechecked both filters and all looked good. Engine started fine but bogged down at about 1,800 rpm with the same old black smoke. Checked pump pressure via secondary bleed and had good pressure while idling. Removed and cleaned air filter. Checked mixing elbow and exhaust hose for debris and found none. Water flow and temperature from exhaust normal. Although, I noticed diesel fuel mixed with black suet floating on the water when engine would start to lose rpm’s and black smoke reappeared. Made sure both fuel tank vent and return lines were clear. Started right up again with the same problems.

Decided to pull and check injectors. Took to a local diesel shop and both pressure and spray appeared normal. Replaced, bled, and restarted with the same symptoms. Starts up on first crank fine. Can idle at 1,000 rpm for 10-15 minutes then bogs down with drop in rpm’s and the return of black smoke; or when I try to increase to 2,000 the rpm’s drop off and engine goes to a stall as the black smoke reappears.

Not sure what to check next. Any and all suggestions welcomed.

where you ever able to figure out was was wrong with you engine. I could have written that i am having the exact same problem and would like to know if you finally figure out what was wrong

[seafarer30]

where you ever able to figure out was was wrong with you engine. I could have written that i am having the exact same problem and would like to know if you finally figure out what was wrong