Urgent! Black Smoke, Low Revs?

sybobcat · 20-06-2009, 09:09

Have 59Hhp Volvo Penta MD22P blowing black smoke and revs to only 1,800 rpm.
The hull is dirty, but it also happens while tied to the dock.
Any suggestions please?

cabo_sailor · 20-06-2009, 09:14

Sounds to me like your exhaust elbow may be plugged. If so you'll need to remove it and let it soak in a muriatic acid solution for a few hours to overnight. This is acid so take precautions with gloves and eyeware. Rinse thoroughly before use.

Rich

Badsanta · 20-06-2009, 10:19

Clean your prop. if your hull is bad your prop is worse. it is also easy to suck up a rope or fishing line. But more than likely the prop is a mass of barnacles and slime. Do you get full RPM not in gear and then in gear low RPM and smoke? exhaust elbow also. Have you used this boat before? Is this a sudden change, or is this after sitting all winter and now just starting?

Sailndive345 · 20-06-2009, 11:02

While you are at it, you may want to see if anything is blocking the air intake to your engine....

Good luck!

Sailndive

sybobcat · 20-06-2009, 17:08

Thanks for all the suggestions so far. I’m going back to the boat today to try them. and will give an update soon. I’m trying to sell my boat and the buyer won’t settle until this is sorted. The main worry is that the problem exists when out of gear and not moving. Wouldn’t that seem to eliminate the dirty hull & prop?? I removed the air filter and got 3,000rpm and less smoke at the dock, but the problem returned when under way.
I then stopped the boat, and tried it again while out of gear, but the problem persisted.
In two days, I’m getting hauled out to clean the bottom. Any other comments please!!

Sailndive345 · 20-06-2009, 17:20

It's interesting that removing the air filter made such a difference - even if temporary... Where does air enter the engine compartment? Do you have some sort of intake duct that is blocked/flattened by something? One way to eliminate this may be to run (if convenient and safe to do so) with the engine compartment open - see if the same behavior repeats itself....

Just a thought - good luck solving the puzzle!

Sailndive

moonrsn · 20-06-2009, 20:41

Did you check to make sure fuel fittings and priming screws are tight? I had this happen to me while test running a Volvo in my garage. I tightened up the bleed screw and it worked fine.

GordMay · 25-06-2009, 07:08

See also a very old discussion “The Smoking Gun “
Interpreting Diesel Exhaust Smoke:
➥ The Smoking Gun

Fishman_Tx · 25-06-2009, 07:19

Possibly too much fuel, too little air, or a crappy glow plug. Not all the fuel is getting burnt. Slow to catch during start?

sybobcat · 25-06-2009, 08:00

Thanks to all. With what we now have in hand , I think we can fix the problem.

Cheers....sybobcat

Badsanta · 25-06-2009, 08:52

Please post what you find. Thanks

sybobcat · 25-06-2009, 08:57

okay...good idea...I'll post what we find in a couple of days....thanks

sybobcat · 27-06-2009, 17:11

A marine engineer elminated the black smoke by running the engine for 4 hours at 2,000 rpm while tied to the dock. He says that, due to the engine not being used for several months, rings were probably stuck inside pistons which were freed up with the high rev running. He also adjusted the 'advance/retard' setting of the fuel injector pump. Thanks again to everyone for your input.

20-06-2009, 09:09	#1
sybobcat Registered User Join Date: Jun 2009 Posts: 10	Urgent! Black Smoke, Low Revs? Have 59Hhp Volvo Penta MD22P blowing black smoke and revs to only 1,800 rpm. The hull is dirty, but it also happens while tied to the dock. Any suggestions please?

20-06-2009, 10:19	#3
Badsanta Registered User Join Date: Oct 2007 Location: virginia Boat: islandpacket Posts: 372	Clean your prop. if your hull is bad your prop is worse. it is also easy to suck up a rope or fishing line. But more than likely the prop is a mass of barnacles and slime. Do you get full RPM not in gear and then in gear low RPM and smoke? exhaust elbow also. Have you used this boat before? Is this a sudden change, or is this after sitting all winter and now just starting? __________________ That derelict boat was another dream for somebody else, don't let it be your nightmare and a waste of your life.

20-06-2009, 20:41	#7
moonrsn Registered User Join Date: Jul 2008 Location: Puget Sound Boat: Islander 37 'Taku Wind' Posts: 33	Did you check to make sure fuel fittings and priming screws are tight? I had this happen to me while test running a Volvo in my garage. I tightened up the bleed screw and it worked fine. __________________ Noel Edwards Faster horses, younger women, Older whiskey, and more money...

25-06-2009, 07:08	#8
GordMay Registered User Join Date: Mar 2003 Location: Thunder Bay, Ontario - 48-29N x 89-20W Boat: C.L.O.D. (Cruiser Living On Dirt) Posts: 12,582	See also a very old discussion “The Smoking Gun “ Interpreting Diesel Exhaust Smoke: ➥ The Smoking Gun __________________ Gord May ~~_/)_~~ (Gord & Maggie - "Southbound") "If you didn't have time/$ to do it right in the first place, when will you get the time/$ to fix it?"

25-06-2009, 08:52	#11
Badsanta Registered User Join Date: Oct 2007 Location: virginia Boat: islandpacket Posts: 372	Please post what you find. Thanks __________________ That derelict boat was another dream for somebody else, don't let it be your nightmare and a waste of your life.

20-06-2009, 09:14	#2
cabo_sailor Registered User Join Date: Mar 2008 Location: SW Florida Boat: Cabo Rico 38 Posts: 283	Sounds to me like your exhaust elbow may be plugged. If so you'll need to remove it and let it soak in a muriatic acid solution for a few hours to overnight. This is acid so take precautions with gloves and eyeware. Rinse thoroughly before use. Rich

20-06-2009, 11:02	#4
Sailndive345 Registered User Join Date: Jan 2009 Location: St Augustine, FL Boat: Beneteau Oceanis 461 - Layla Posts: 162	While you are at it, you may want to see if anything is blocking the air intake to your engine.... Good luck! Sailndive

20-06-2009, 17:08	#5
sybobcat Registered User Join Date: Jun 2009 Posts: 10	Thanks for all the suggestions so far. I’m going back to the boat today to try them. and will give an update soon. I’m trying to sell my boat and the buyer won’t settle until this is sorted. The main worry is that the problem exists when out of gear and not moving. Wouldn’t that seem to eliminate the dirty hull & prop?? I removed the air filter and got 3,000rpm and less smoke at the dock, but the problem returned when under way. I then stopped the boat, and tried it again while out of gear, but the problem persisted. In two days, I’m getting hauled out to clean the bottom. Any other comments please!!

20-06-2009, 17:20	#6
Sailndive345 Registered User Join Date: Jan 2009 Location: St Augustine, FL Boat: Beneteau Oceanis 461 - Layla Posts: 162	It's interesting that removing the air filter made such a difference - even if temporary... Where does air enter the engine compartment? Do you have some sort of intake duct that is blocked/flattened by something? One way to eliminate this may be to run (if convenient and safe to do so) with the engine compartment open - see if the same behavior repeats itself.... Just a thought - good luck solving the puzzle! Sailndive

25-06-2009, 07:19	#9
Fishman_Tx Registered User Join Date: Apr 2009 Location: Beeville, Tx. Boat: 1973 Bristol 34 - "Our Baby" on the hard in Rockport,Tx. Posts: 468	Possibly too much fuel, too little air, or a crappy glow plug. Not all the fuel is getting burnt. Slow to catch during start?

25-06-2009, 08:00	#10
sybobcat Registered User Join Date: Jun 2009 Posts: 10	Thanks to all. With what we now have in hand , I think we can fix the problem. Cheers....sybobcat

25-06-2009, 08:57	#12
sybobcat Registered User Join Date: Jun 2009 Posts: 10	okay...good idea...I'll post what we find in a couple of days....thanks

27-06-2009, 17:11	#13
sybobcat Registered User Join Date: Jun 2009 Posts: 10	A marine engineer elminated the black smoke by running the engine for 4 hours at 2,000 rpm while tied to the dock. He says that, due to the engine not being used for several months, rings were probably stuck inside pistons which were freed up with the high rev running. He also adjusted the 'advance/retard' setting of the fuel injector pump. Thanks again to everyone for your input.

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Black Smoke Yanmar 2GM20	jmdezzutto	Engines and Propulsion Systems	23	11-11-2009 11:32
Fouled Injectors > Low RPM & Smoke?	Northeaster	Engines and Propulsion Systems	30	11-05-2009 15:26
Yanmar issues... white smoke and black oily soot (exhaust) and engine smoke	CS27	Engines and Propulsion Systems	3	14-09-2008 18:40
M12 black smoke under load	bmiller	Engines and Propulsion Systems	26	16-08-2007 13:35
This Can't Be Good.... Black Smoke & Soot	markpj23	Engines and Propulsion Systems	17	04-06-2006 07:35