Black Soot

[Stinkpot]

Two part question:

First, some detail:

• 36' Calvin Beal
• 370 hp Yanmar 6LYA-STP (currently 350 hrs on it)
• 2:1 ZF xmssn
• four blade 24 x 20 prop
• typically run at 2200 - 2600 rpm (max 3325)
• Use FPPF fuel treatment with cetane booster
• Wet exhaust which exits at the waterline on port side about 1 foot fwd of transom

Been through the whole "typical causes of black smoke" list with Mack Boring which led to the prop adjustment from 24 x 22 to 24 x 20, cleaned turbo, use fuel treatment, run engine at higher rpm's than I used to. The only recommendation I haven't tried is checking the injection timing, but I see no other evidence that it could be off.

Question 1: Why am I constantly taunted with a dirty transom after only a few hours of runnning?

Question 2: If a perfectly clean exhaust isn't in my future, how can I keep the transom clean? I read that a formica cleaning product, "Gel-Glos" when applied like paste wax to the transom works, will try in 2012. Any other good ideas out there?

Thanks!

 

[Pedlyr]

Do you have an aftercooler? If yes, is it dirty?

 

[captainlarry84]

I concur with your propeller size. There is no way you could have turned a 24 X 22 four blade on a 36 foot boat. Even the 24 X 20 is a push with a boat that large. Yanmars burn very clean if you run them @ 2800 plus. At lower speeds they tend to load up a bit and when you throttle up you get the cloud of smoke.

On your additive stick with the FPPF but try their Lubricity Plus Fuel Power with the blue label.

I also assume that you are using premium grade diesel and not # 2 oil off the home heating truck, which in a Yanmar can be a problem.

Also make sure that you engine room is getting enough air to mix with the fuel. If you are air starving the engine room the motor will draw more fuel to make up the difference. Yanmars rev high and need a lot of air flow. A simple test is to run your boat a WOT then pop the engine hatch and study you tachometer. If it moves up at all then you have an air flow problem.



Lastly photo tach your panel and make sure that your tach is correct. You are still swinging a big wheel in a big boat for that motor. I am sure that a 2:5 gear would have put you in the sweet spot with a nice 24 X 24 wheel spinning nice and slow.

 

[BillD]

Has to be one of three causes.

1. Lack of air to the engine.
2. Engine overload.
3. Station wagon effect.

OR

Perfectly normal to have soot on transom.

 

[captainlarry84]

1. Lack of air to the engine.
2. Engine overload.
3. Station wagon effect.

1. easy to check just pop the hatch at WOT

2. easy to check you must get 3300 RPMs on your tach at wot

3. Not sure if that happens at 15-16 knots

I have a 370 Yanmar with 2:0 23 x21 wheel in a 31 JC. I do get a little soot but nothing that is very noticable.

Also check your turbo is the paint discolored? that is also a sign of heat & load.

As stated earlier a 36 footer with a wheel that is the same as mine in a 31 footer is a lot of load. As a 24 X 20 is the same as spinning a 23 X 21 as far as load goes.

 

[Stinkpot]

I am using premium grade fuel, unlike my neighbor who has the home heating truck top him off... Have an aftercooler, which was cleaned out at around 200 hrs with no change in exhaust condition. Also, tried cruising from Mystic to NYC with hatch up to test the lack-of-air theory with no change; still had to scrub the transom afterwards.

Don't know about engine overload; I am able to get just over the 3300 rpm at WOT the engine is rated at, so I think I'm good there, and the tach was verified at commissioning too.

Maybe it is perfectly normal, if so I'd love to find an easier way to clean (and keep clean) the transom. It just feels like I'm the only one who has to clean off my transom at the end of the day.

Thanks!

 

[captainlarry84]

If your are just getting 3300 RPMs it might be a good idea to photo tach your boat & make sure that your panel tach is reading coreectly. A photyo tach is less than $100.00. At the start of each season I always d9o the photo tach test to make sure that my panel is correct. Many times these panel tachs are off by as much as 200 RPMs. Than can cause you a lot of headachs down the road.

Lastly to remove soot I use Spray 9 & a white 3 M pad. Spray it on spread it around let is sit a few minutes then gentle wipe with the pad.

Also do you have an exhaust flap. If not put one on. It will shoot a lot of soot away from the transom. On my boat I get two lines of soot on both sides of the flap with little on the stern. I think it is the flat that helps keep me pretty clean.

 

[Stinkpot]

Spray 9 - good stuff. Glad the sales rep handed me a free bottle at a boat show a few years ago; all I use onboard now...

I like the exhaust flap idea, but here's my exhaust, and I still get the "station wagon" effect, worse on the port side of the transom and hardly any on the starboard side of the transom:

 

[BillD]

There may be zero station wagon @ 15-16 knots but in my mind there
is station wagon effect "at some point" between 5-16 knots.

The engine is under maximum load or overload while getting "up on the water a bit" to speed and you have soot on the transom.

Photo tach is imperative unless the boat has a digital tach like Aetna.

AND the overload riddle could be solved easily with an EGT reading

FWIW,

Bill D

 

[captainlarry84]

Your exhaust exits in front of the transom so I could see how the soot can whip around. Maybe a small fiberglass visor molded in on the top of the side exhaust will direct the soot down and into the water before it gets air born and sucked onto your stern. A flap will not work because of attachment issues. The visor would be pretty easy to make by using a small piece of the next size large fiberglass tube cutting it to shape and fairing it in.

 

[CEShawn]

I had a pair of 6LYA-STE's (350HP) back in 2000 I believe to some level the first that Mack Boring pushed through. I spent two years dealing with sooting issue's up and down and just believed the matched my boat wrong. I totally agree with all the above for good idea's and maybe you will find it. I cannot think how many times MB was down to our boat, how many times it was timed, changed injectors and everything else. I really think after that there was alot to be said about not all Yanmars are created equal. I know several boat builders who love things about them but will swear up and down that they put one engine in one boat, build another boat and it doesnt have the same power.

One thing my 26' boat has with just a 200HP Volvo on it and wondering how big they make them is one of those Salisbury Mufflers. I do not get a hint of soot on my boat, exhaust is sent right down into the water and also includes a ball to not flood water back. I forget my exhaust size but imagine a larger size would be ugly and of course always have to worry about back pressure. We regretted changing that boat to twin yanmars I can tell you that and still to do this day do not think I would buy a Yanmar, even though I know several people who have 5,000 and 8,000 hours on it, give it bad fuel and love them, its just all a preference.

 

[steveinak]

I am using premium grade fuel, unlike my neighbor who has the home heating truck top him off... Have an aftercooler, which was cleaned out at around 200 hrs with no change in exhaust condition. Also, tried cruising from Mystic to NYC with hatch up to test the lack-of-air theory with no change; still had to scrub the transom afterwards.

Don't know about engine overload; I am able to get just over the 3300 rpm at WOT the engine is rated at, so I think I'm good there, and the tach was verified at commissioning too.

Maybe it is perfectly normal, if so I'd love to find an easier way to clean (and keep clean) the transom. It just feels like I'm the only one who has to clean off my transom at the end of the day.

Thanks!

That Castrol Super Clean stuff does a good job of getting soot off.

 

[tunaorlater]

I find the best thing to get it off is salt water. Dip the brush right into the canal and wipe it off. Naturaly you do have to clean it after but the 1st step is always the salt water.

 

[BillD]

That Castrol Super Clean stuff does a good job of getting soot off.

It does Steve, takes all the dam wax/polish off with it !!! LOL.

How is Alaska?? cooling down a bit????

 

[Frigate]

Try using Wisk. It takes the soot off real easy and leaves the wax. After saltwater it is the cheapest product brought up yet.

 

[steveinak]

It does Steve, takes all the dam wax/polish off with it !!! LOL.

How is Alaska?? cooling down a bit????

Its cold,snowy and dark, i can get up at the crack of dawn easily,it comes about 9:50AM and its pitch dark at 4PM. We were gone for a few weeks and then it was real cold down to -20 so 20 above now is down right hot.

 

[BillD]

Nice !!!!!

 

[GoodChance]

Steve -

I can easily see why alcoholism and drug-use is high in Alaska..... the sun only being up for 6hrs a day and never get above 20-degrees would make me drink too.

While Alaska is a great State, I could live there year-round under those conditions.

 

[BillD]

You'll find yourself.......

in a rehab program yourself @ the pace this 32 Holland "rebuild" is coming along!!!!

 

[steveinak]

Steve -

I can easily see why alcoholism and drug-use is high in Alaska..... the sun only being up for 6hrs a day and never get above 20-degrees would make me drink too.

While Alaska is a great State, I could live there year-round under those conditions.

We got our share of drunks and druggies thats for sure, seams like the lice always attract more lice! The good part is that after the 1st of Feb we start gaining daylight fast like 6 min. a day so in no time we've got plenty of daylight. It does get above 20 where i live in fact last week it was just about 40 for a couple of days, that sucked cause it melts all the snow and it just turns into black ice on the roads. I really can't think of a better place for me to live right now, this place has been very good to me but usually its not the place that makes it good its what you make of it to make it good.
25 and snowing this morning but no wind, its going to be a great day!!