Black Exhaust Marks

dudders · 12-03-2007, 10:40 AM

Hey guys,
I have noticed that each time I take the boat out, when I get her out of the water, the stern is all black, and looks like it has come from the exhaust.
Does anyone else get this????
I run the best BP high octane petrol (gas) and have had the engine tuned up not long ago.
Its not too hard to get off, but a bit tricky in some spots. Is there a good product to get rid of it?
I will take photos before I give her a bath next time out so you know what I'm talkin about.

Z 202 · 12-03-2007, 01:33 PM

Yep. I get it. If the hull has a good wax it usually wipes off fairly easy. Mr Clean magic erasers make short work of the tough ones.

WetWilly · 12-03-2007, 06:09 PM

Hi dudders,

Sounds like your running a bit rich on the air/fuel mix even with the good gas and a tuneup.

The best way to check if the A/F mix is good is to remove a couple of sparkplugs and look at their color/condition.

Here is a little info I found on the web:

"Spark plugs....We can make this easy or we can make it hard. Let's start with easy. After running for a while normally, stop the bike and take the spark plugs out. They should look a light chocolate brown in color. If , black and sooty the engine is running too rich in the fuel departement or too cold of spark plug. If black and shiny (oily) they are oil fouled. If they are whitish you are running too lean a fuel mixture and/or wrong ignition timing or too hot of spark plug. When you see this, your engine is about to blow up!!!

Now the harder stuff. A spark plug does not make your engine run hotter or colder. The terms hot or cold refer to the temperature of the tip of the spark plug itself. The plug must keep a temperature of, between 752 and 1652 degrees Fahrenheit. If it gets too hot it can fire off the air/fuel mixture at the wrong time. This can cause detonation and/or pinging which will put a hole in your piston... not good. If it gets too cold it will not burn off the carbon and fuel deposits on it's tip and the plug will foul out (stop working) not good either.

The heat range of a spark plug is controled by the length of the center electrode. A longer one is hotter because it takes longer for the heat to flow through it to the cylinder head. As you might think the cooler plug has a short center electrode.
Spark Plugs Hot and Cold

To get a true plug color reading you must run the engine, at the throttle setting that you want to test, for about a mile, then kill the ignition and coast to a stop. Then pull the plug and look at it.

As the engine ages and more oil gets past the rings a hotter plug may be in order. If you drive at low speeds all the time a hotter plug will keep the plugs from fouling. If high speeds are your thing, a cooler plug may be just the ticket. Don't be afraid to pull that plug out and give 'er a read!"

Here's a link with pics of what you do and don't want a plug to look like: http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

Could be as simple as running a hotter plug or maybe your carb/injection system needs a little adjustment.

As for the film, I use orange mechanics hand soap without pumis or grit! It comes in a large pump container and is kind of thick. I use a large paint brush to get into the tight areas. Just use a strong stream of water, the stuff cleans grease, soot and grime without hurting the finish. Lastly, as Z 202 said, finish with a good coat of wax to make it easier next time.

Good luck and let us know what you find out!
WetWilly

dudders · 12-04-2007, 09:22 AM

Thanks for the info guys - you have obviously gone to a lot of trouble for me WetWilly so thankyou for that
. I have the boat in the shop today getting the vibration looked at. I will call in next week and see what the go is.
They said they were going to go for a sea trial with me next Tuesday, so when we get her out of the water I will point it out to them (Murphy's Law - there will be no black marks!!).

I like the looks of your new boat Wet Willy - Would that be the new 12 foot Bayliner base model??

***mikeyt*** · 12-04-2007, 04:49 PM

i dunno Dudders....if you have black marks on your backside i think you need to change your diet more than anything else..

***indykoch*** · 12-04-2007, 05:00 PM

Or try spending a bit more time wiping!!!

WetWilly · 12-04-2007, 06:43 PM

Quote:

Originally Posted by mikeyt

i dunno Dudders....if you have black marks on your backside i think you need to change your diet more than anything else..

Quote:

Originally Posted by indykoch

Or try spending a bit more time wiping!!!

Aw jeez , youz guys are just too raw............... then again, maybe a little more fiber wouldn't hurt!

WetWilly

WetWilly · 12-04-2007, 07:56 PM

Quote:

Originally Posted by dudders

I like the looks of your new boat Wet Willy - Would that be the new 12 foot Bayliner base model??

Hi dudders,

Your close! It's actually their original six foot "expand 'a' boat". Got a couple of friends, add another leaf, need a sun deck? No problem, add a couple more leafs! As you can see, this model sports the latest in trim technology, bow up, sit back, bow down, sit forward, simple! Another feature is the state of the art Navigation unit. Just center the place your going to in-between the front uprights and you'll be there soon enough, turn the boat around to reverse the procedure and go back. Look at the craftsmanship of the 100% authentic California Redwood (rot and termite resistant) hull and safety rails (rope not included)! And last but not least, when you’re not boating, flip it over and it doubles as a dinning table equipped with its own salad maker/deli slicer! Although you might want to use a table cloth as the bottom can get a bit slimy. Now top that…..

WetWilly