Cleaning diesel soot

Joint Custody

Joint Custody

Well-Known Member
Sep 20, 2017
1,254
Lake Powell Utah
Boat Info
2001 460 Sundancer
Engines
Twin Cummins 6CTA8
Im new to the Diesels. I am loving everything about them other than the soot that gets on the transom , swim deck, and the light film in the cockpit.

Any suggestions on the best way to keep it cleaned up easily?
 
You should not be getting soot to start with; at least in any noticeable amount. Probably should look into why.
The best cleaner for soot that I have found is Z Cleaner. I get it at West Marine.
 
I second TTmott as far a reducing it. Soot is unburnt fuel so my guess is you may be overpropped. What are your WOT RPM's?

Josh
 
NotHerDecision said:
I second TTmott as far a reducing it. Soot is unburnt fuel so my guess is you may be overpropped. What are your WOT RPM's?

Josh
Click to expand...
Thanks
It isnt heavy soot just a light film at WOT I am getting 3000 rpm . At cruising I run around 2200 to 2500 at 2500 getting 20mph on the GPS . Lake Powell Ut is around 3700 feet.
 
I pulled the boat and blocked it sunday and will be going back to the lake in a couple weeks . I forgot to get the prop size when pulled . This boat has been on the lake since brand new so I am assuming it was set up for this elevation .. however you never know.
 
Joint - do you have Cummins or Volvos?

The reason that I ask is all, and I mean ALL, of my Volvo friends (about 4 in Chattanooga) have trouble with soot...
 
Do you have cummins? Your WOT shouldn't be anywhere near 3000K. Wondering if your tach is off.

Josh
 
I'm really thinking your tach's are off. Your WOT should be 2650-2750.

I think you should verify the rpm with a different instrument, but if that WOT is accurate then you need some prop work.

Josh
 
Joint Custody said:
Cummings -WOT is 3000 at 26.5 MPH on GPS.
Click to expand...

It's almost impossible to trouble shoot over the internet, but you're getting good feedback from the guys above. Definitely check the rpms with a laser tach as 3000 is the high idle rpm on the 6CTA 8.3 Cummins. In other words, the motors should turn up between 2920 and 3020 rpm in neutral with the throttles pushed wide open. So you can see why we are saying that you are not really turning 3000 while underway. WOT while underway should be as others have said, 2600 rpm MINIMUM, 2700 is better. Confirming your real rpm is where you have to start.
Laser tachs can be had for as low as $10 up to a few hundred. The laser tach that I have cost less than $30, It is something that everybody should have in their tool bag for that money. Good luck and let us know what you find out.
 
Just to follow up on this post.

I had the boat blocked for a couple months .
Just put back in the water yesterday and ran the 100 miles north back to the slip.

As recommended. I purchased a laser rpm gun. My tachs are around 400 RPM off... they are reading to high.
WOT was 2650 on both engines and 31 mph on GPS. Mt props are Hy Torq 23R26 H-Cup.

Thank you all for the advice on doing the RPM reading. We still a very very light dusting of soot on the transom and cruising back north with the full enclosure up we get a little dusting of soot in the cockpit as well.
 
Black Streak Remover seems to work well. I buy the cheapo stuff in the RV section at a Walmart.
 
Sounds like your right on as far as your props! That's amazing and awesome. As far as the Soot, treat the fuel per Frank Webster's reccomendations on the front page and run through a full clean tank on both sides. Make sure your filters are clean as well and I'll bet the soot goes away on its own. If not, look at some engine tuning... Have you had a valve job?

Josh
 
NotHerDecision said:
Sounds like your right on as far as your props! That's amazing and awesome. As far as the Soot, treat the fuel per Frank Webster's reccomendations on the front page and run through a full clean tank on both sides. Make sure your filters are clean as well and I'll bet the soot goes away on its own. If not, look at some engine tuning... Have you had a valve job?

Josh
Click to expand...
Good advice!

I just had the 600 hour service done and everything checked out from the Tech. Had the valve lash done.

I have run one tank all the way through with Franks plan... and plan on doing one more.
 
I feel like some film happens with diesels no matter how clean they're burning, especially from a generator.

Since the soot/film/streak is fuel/oil, it's grease, so a de-greaser works fine.

Whenever I raft up with my friend's 450 and I get the "generator side," I always depart with a small but manageable black mess on the side of my boat. If cleaned off right away, it's never a problem.
 
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