Boring Engine question

Nov 30, 2009
80
Oday 28 Lake Michigan
Like all boat lovers, I spend time during the summer cruising the docks in the summer, and website in the winter. I live in Michigan. One of the things I've noticed while looking at the engines on the "Boat for Sale" website is how nice and clean the engines are. Now I know a person selling their boat is likely to clean the engine compartment, .....but My iron jib, a universal diesel on a 28 ODay, is covered in fine black dust/soot. What could the issue be? What should I look at? I've casually looked at the exhaust. It does not seem to have any location with real heavy concentration of the dust (hole or corrosion). It has the same amount has all the rest of the engine. Is this just "common" for a diesel?
 
Apr 5, 2009
2,774
Catalina '88 C30 tr/bs Oak Harbor, WA
A common cause of black dust on the engine is belt dust. It is caused by misalignment of the pulleys or too big of a load on the alternator.
 
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Likes: glaufman
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Could be as simple as a damp rag now and then.
 
Nov 30, 2009
80
Oday 28 Lake Michigan
Could "to big of a load" be running the engine at too high of a RPM. I do not have a tach and I will admit to pushing a couple of times last year for higher speed than maybe I should have.
 

Harlan

.
Jun 4, 2004
99
Oday 34 Niantic
I agree belt dust is #1. Also you are likely getting a little oil mist from the crankcase vent. The alternator fan does a nice job of circulating that throughout the engine compartment so the belt dust becomes sticky and greasy. Run the crankcase vent hose to a little oil separator and then back into the air filter so it is pulled back into the engine. I'll swear there is a write up on specifically how that is done on SBO but I can't seem to find it at the moment. I've done it - works great.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Belt dust and oil breather hose. Run the breather hose to oil separator and then air filter.
 
May 29, 2018
457
Canel 25 foot Shiogama, japan
Could be as simple as a damp rag now and then.
To keep the engine shiny clean and prevent rust, I use a rag soaked in diesel fuel. Wipe over every month or so.
(Of course the rag is disposed of correctly)
There is a bit of a smell, but it's an engine not a showpiece.

gary
 
Jan 7, 2011
4,723
Oday 322 East Chicago, IN
My O’Day 322 has a Yanmar 2GM20 engine, and it was pretty black with the same kind of dust you describe. I sprayed it with some engine cleaner, followed by some water to rinse it off. Wiped it down and cleaned up the bilge, and ta da! All bright and shiny. As others have said, a wipe down every once in a while to keep her looking good. I also changed out the worn belt with a new one.


Greg
 
Jan 7, 2011
4,723
Oday 322 East Chicago, IN
Do you remember what you used?
I don’t recall specifically...just some engine degreaser. I did it in the winter, and only had a garden sprayer of water to “rinse” it off...so did not use a lot of water.

Greg
 
Aug 11, 2011
857
O'day 30 313 Georgetown MD
Could be your exhaust manifolds gaskets are worn and or bolts need to be torqued down. I recently got the engine started after a three year none use. Black dust or soot flying everywhere. Shut it down, R&R the manifold, tightened the studs into the block and torqued down the nuts. All done, no soot.