Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 21-04-2011, 10:35   #1
Registered User

Join Date: Aug 2010
Location: Key West, Houston bound.
Boat: 1979 28' Mariner Sloop
Posts: 17
1GM-10 Black Sooty Exhaust

We were beating into 17 knots of winds, waves and current yesterday. We were making 2.7 knots at about 3/4 throttle. We went up to full power to see what she would do (about 3.5 knots) and after about 30 minutes started to get a little smoke and black sooty exhaust water. We also lost some power without losing rpms. We trapped some of the exhaust in a bottle to confirm that it was not oily and once we throttled back down the exhaust coming out was clean. We did a few tests over the next hour or so and when we revved up to full we would get the black soot. Our power was all over the place as well after that regardless of how much throttle we were giving her. Sometimes 3 knots and sometimes falling to 1 knot or less without any change in wind or waves etc.
After returning to the slip (we motored about 8 or 9 hours total) we talked to a few folks and checked online. We think it is likely we had fouled our prop, which also has a small amount of growth on it. We had not experienced that before and did not know how it felt to happen. We reversed getting into the slip and may have released some seaweed. When I dove in with a mask there was a handful of weed loosely on the shaft at the prop. I also noticed a bigger ball of the same type of weed floating in our slip which may have come off when we reversed in.
So ultimately, we plan to change/clean the air intake, polish our fuel and proceed ahead.
Does anyone have experience with a problem like this? Do you think our engine should be able to pull us along against wind and waves at 3/4 throttle? (Until we started with diminished propulsion we were making 2.5 knots) Do you think fouled prop could be a reason for our engine to behave like this? Thanks in advance for your helpful advice.

Wunu is offline   Reply With Quote
Old 21-04-2011, 10:43   #2
Registered User
Astrid's Avatar

Join Date: Oct 2008
Location: Canada, up on Hecate Strait in sight of Alaska
Boat: 50-ft steel Ketch
Posts: 1,821
Send a message via MSN to Astrid Send a message via Yahoo to Astrid
Re: 1GM-10 black sooty exhaust

Could well be the case--rather like a heavily loaded tractor trailer rig having to pour on the fuel to go up a long incline. Now that you have unfouled your prop, take her out again and see if it is still doing it. If it is, your problem is somewhere else; if not, all well and fine.

Astrid is offline   Reply With Quote
Old 22-04-2011, 07:27   #3
Registered User
lorenzo b's Avatar

Join Date: May 2009
Location: Panama
Boat: Steel trawler 63' Eileen Farrell
Posts: 960
Re: 1GM-10 black sooty exhaust

Start by checking you air intake filter and making sure the engine gets enough air. My gen set started belching black smoke and just removing the air filter cured it. If it's plugged it will be hard to pull it off if the engine is running due to the suction. You need a filter so get a new one.
lorenzo b is offline   Reply With Quote
Old 24-04-2011, 07:43   #4
Registered User

Join Date: Aug 2010
Location: Key West, Houston bound.
Boat: 1979 28' Mariner Sloop
Posts: 17
Thanks for the advice. It seems the engine has eaten the air filter!! Only the armature remained so we replaced it. We took her out Friday and she performed admirably, so we really think we had fouled the prop with weeds and she was spinning wildly with little resistance. We have learned about 500 things every time we have taken her out.
Wunu is offline   Reply With Quote
Old 25-04-2011, 14:43   #5
Marine Service Provider

Join Date: Feb 2011
Location: St Petersburg, FL
Boat: Thompson Trawler, SUITE 44
Posts: 73
Re: 1GM-10 Black Sooty Exhaust

If you have an Yanmar, I would think the mixing elbow on the exhaust,
otherwise I would check for fuel contamination.

"Suckin Sludge & Havin a Gas"
ATC is offline   Reply With Quote


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Runaway Yanmar 1GM Chief Engineer Engines and Propulsion Systems 2 29-10-2009 23:08
YANMAR TACHO (1GM) bill good Engines and Propulsion Systems 0 06-05-2009 17:39
Black water from 2gm exhaust Aquah0lic Engines and Propulsion Systems 31 16-01-2009 13:35
Yanmar issues... white smoke and black oily soot (exhaust) and engine smoke CS27 Engines and Propulsion Systems 3 14-09-2008 17:40
An exhausting sooty matter! seafox Construction, Maintenance & Refit 11 16-07-2006 00:51

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:13.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.