Diesel Ignorance

[Annapolis E-27]

I have an old Yanmar YSB-8 that has not been run much this season. Today it started fine as usual but when put under load it released an awful lot of heavy black soot onto the water. I ran it this way for about 20-30 minutes and it continued. It was not oily at all, just soot. At idle this seems to clear. Any suggestions would be greatly appreciated.

Mark
Evening Tide E-27

 

[NateHanson]

Check your airfilter, to make sure nothing has crawled in there and died. It might not be getting enough air.

Or perhaps the thermo is stuck open, and not allowing the engine to heat up to operating temperature. What's the temp gauge say?

(These are really just ideas, I don't have much more than an operational relationship with my yanmar. )

 

[Annapolis E-27]

Thanks...I would do both except my old YSB-8 doesn't have either an air filter or a temp gauge. I will check the thermostat though.

 

[diamondjim]

Black soot

Black soot is an indicator of rich fuel to air mixture. (white smoke indicates a lean fuel/air mix) Simple things first - as one suggestion posted, check the air intake carefully for obstructions. If you are satisfied it is clear, then the fuel delivery rate from the injection pump might be too high for a certain throttle setting - maybe. Check your crank case oil for diesel contamination. If so, your oil level might be higher than the last time you checked oil.

Dirty fuel injectors will give black smoke as well. The injector needles do not spray fuel properly, leak or dribble fuel (poor atomization) causing black smoke. Treat the fuel (clean fuel) with Red Line or equivalent fuel treatment to clear the injectors.

Also, might you have a load of bad fuel? To check, drain some fuel from the tank line into a quart glass jar and check for cloudyness, water and other junk.

Hope this helps,
<> Jim

 

[NateHanson]

Thanks...I would do both except my old YSB-8 doesn't have either an air filter or a temp gauge. I will check the thermostat though.

It's got an air intake though. (some of them have a simple wire screen too to keep particulates from the bilge out of the cylinders). Look in that big hole and make sure it's not obstructed. That would be consistent with it only running rich when you throttle it up.

 

[Annapolis E-27]

The air intake appears clear and the fuel looks good. I did add some injector cleaner and have run about a gallon of fuel through under load with no real change. I am still at about 50% power, even less in reverse, and am putting black soot out with evry pulse of water through the exhaust. I will run it for another hour today and see if it begins to clear. I would rather be sailing.

 

[stbdtack]

Black smoke....

Had a YSE12 on a previous boat.
Is your prop clean? sounds like its overloaded.
Is it turning up to rated RPM?
The Yanmar mixing elbows are prone to rust and clogging too. This will choke down the motor. All that soot will quickly contribute to the clogging. Take off your exhaust hose and look up into the elbow with a light. At least this will verify if its clogged or not.....

 

[Jeff Asbury]

See if these guy's have any answers for you.

See if these guy's have any answers for you. http://www.yanmarhelp.com/

I have a 1GM10 and had to do a top end rebuild a year ago because there was no exhaust riser installed. Salt water was running back into the mixing elbow and the head when the engine wasn't running. My guess is the this little motor was drinking salt water ever since it was installed some time in the eighties, long before I purchased the boat.

I had quite a bit of soot before it finally croaked and I found out what the problem was. I had my mechanic fabricate a exhaust riser and we eliminated the mixing elbow completely. Make sure you mixing elbow and exhaust system is above the water line. Not sure if this may be your problem or not. Good Luck!

Check out the photos of what happens when a exhaust system is improperly installed.

 

[Jeff Asbury]

Exhaust Riser

EXHAUST RISER, SEE PHOTO.

 

[Annapolis E-27]

Thanks...I will look at the mixing elbow tomorrow. Cleaning the prp might be another story as the sea nettles have invaded Whitehall and Mill Creek. Also Jeff, does the 1GM10 fit on the same footprint as the original YSB-8 or Atomic 4? That is a nice looking installation.

 

[Geoff Johnson]

On my boat the mixing elbow is below the water line, but the raw water injection line is looped above the water line with a siphon break at the high point. The siphon break is a hose that leads all the way from the engine to a nipple on the bronze exhaust thru hull, so I assume it is squirting water out there as well as into the elbow when the engine is running.

 

[Jeff Asbury]

Mark,

No, the footprint was not the same as the A4. If you look close you will see elevated aluminium extruded support beams that rest on the original fiberglass platforms. I am not sure but I am inclined to think the boat had one of the earlier diesels that were offered as a option. Volvo or Universal. I don't know for sure because the boat was a Repo with no history available. I don't have the same engine control panel that was part of the breaker panel on the port side of the companion way. No ignition (key) as on the A4 boats I have seen. My Father had the YSB-8 in his Bayfield 25 and never had any trouble with it in 25 years. I am sure his exhaust was a factory installed by Bayfield Yachts.

Geoff,

I have the siphon break or valve as well. It has it's own little thru hull as well. It just weeps a little bit of water as it is supposed to according to my Yanmar Mechanic. I found out the exhaust is more complicated than I ever thought. Riser, Anti Siphon Valve, Muffler Box and so on.

 

[Jeff Asbury]

This diagram came from the http://www.yanmarhelp.com/ web site.

This diagram came from the

http://www.yanmarhelp.com/

web site.

 

[Annapolis E-27]

Jeff,

That diagram is exactly what my YSB-8 system looks like. Thanks....

 

[Annapolis E-27]

The bottom and prop were cleaned today by a diver. We shall see if that does does the trick. I will tell all tomorrow.

 

[chaco]

Prop Overload !

Had same problem on the 74' 35II.
Rebuilt the injectors. Dumped all the "old stinky" fuel. Installed a 2 micron
pre-filter. Changed air cleaner element.....still ran at half power and belched
black smoke. Our local resident "real" dock mechanic helped me with all this
and was still BAFFLED! He said the prop must be bound up. We inspected the
shaft turning out of gear and the shaft was free.
So.....I dawned my snokel and mask......and dove down to inspect the prop.
There was no prop, just a thing that looked like an underwater Christmas
Reath ! Maybe I should get a hull cleaning service....eh?
I have since cleaned the prop, replaced the old rusty steel tank and have a
monthly hull cleaning service. The boat runs GREAT !
I am also glad that I prefomed ALL the other upgrade installations, now I have
a service record on a 30 year old boat with a sketchy past

Ya just never know...do ya !

Good luck on your engine project

Dan Simpson
Merlin
1974 E35II
Oceanside Harbor, CA

 

[Annapolis E-27]

All it took was a diver

I think his quote was "those were the largest barnacles I have ever seen and they were on both sides of the prop.

Problem solved......

Mark