I Emailed Merc / 496HO soot

[Beer-30]

Don't waste another dime, just wipe it down.
K26
I'm really starting to think that way. I think if I end up changing rockers and then later adding exhaust, it will clean it up to an acceptable level. We'll see.

[Kachina26]

I'm really starting to think that way. I think if I end up changing rockers and then later adding exhaust, it will clean it up to an acceptable level. We'll see.
Rockers might change things, (I doubt it) exhaust won't change a thing. If you like, I'll be happy to scan it for you and tell you that there are no codes for half what you've been paying

[Not So Fast]

K&N P/N 59-5005 K&N (http://www.knfilters.com/marine/boats.htm)
I got mine from Vic Hubbard Speed and Marine. Best price I found (online)
59-5005 (http://vichubbard.com/shop/home.php?...ction=0&page=5)
Vic Hubbard Speed & Marine
Phone: (800)683-1646
Fax: (510)887-6322
URL: www.vichubbard.com
No, i am not affiliated, I just pass on info from companies that treat customers right!
Good info D.B. thanks NSF

[Sane Asylum]

Well, the way I would word it on a GM repair order is VOS. Vehicle Operating to Specifications. Sometimes, normal operation is not a desireable operation. But, that's the way it is. Kinda like when you hit the recirc button on the AC control head and the compressor kicks on. You don't want cold air, you just want to eliminate the fumes from that stinking diesel truck in front of you. Or, like when I replace the memory seat module on an 05 Yukon. Before I change it, your seats, radio, a/c and mirrors all changed to your previous settings with the push of a button on your remote. Afterwards, none of that happens until you push the button on the inside door panel. And even at that, only the seat and mirrors move now! (Due to a software change). Or, perhaps like the slight whistle noise when the a/c compressor comes on on the GMC Canyon's. Normal, but not acceptable. (ok, they have a bulletin for that now. But, I had to tell a few customers to deal with it for the first year). I guess what I'm saying is, Mercruiser wants engine longevity, and they are achieving it through a rich mixture. So, we as consumers have to buck up and wipe the transom down more often. Don't waste another dime, just wipe it down.
K26
There you have it folks.........I agree. I did speak at length with a buddy of mine who is a GM tech (12 years) and he said the same thing. Slightly rich is a good thing. Rich is cool, lean is hot............blah, blah, blah.....
After my discussion with him I felt better and just got used to wiping it down.
Believe it or not, the design of swim platform(integrated) has a whole lot to do with it. If the soot/unburned fuel/spent gases have no where to go, they're gunna stain something. Next time you see a Baja outlaw with stock 496's (HO's or mags) look at his transom with the aluminum platform. It's clean. That's another reason I gave up......
Beer 30.........Your quest is admirable but you better get a rep on your side. I could never get anyone to call me back on my out of warranty issue.....
May the force be with you...... :wink:

[Just Tool'n]

Ok here is my possible fix to the problem, somewhat related.
I have an Eliminator 28ft Eagle. After a motor upgrade last year, going with a Whipple S/C on a 454MPI, with an old MFEI-1 system the back of the transom was allways sooty.
What a pain in the ass!
The State of California fixed my problem for me!
How?
It's call J-2005, we all know it as the new sound law.
I put Gibson exhust tips on the Eliminator, to comply with the new state law.
Besides making the decibel level lower I now do not have the black soot on the transom, due to the fact that it moved it out away from the back of the boat.
This is about the only time that goverment intervention ever helped fix anything in my life!
Has anyone else had this help with this problem?
I know mine is not the 496MAG, & I have allways read about this problem, maybe this might help!
Just trying to help.

[Beer-30]

Thanks for all the tips, guys. Kachina, thanks for the offer, what a pal :hammerhea
I would really like to get the DIACOM software and cables, but they are a little pricey for just being able to see parameters and not change anything. I had some laptop software for my Grand National regal that could alter boost and fuel maps. Wish there was one for the PCM555!
The other reason mufflers cure the problem is; it gives the soot something to cling to prior to exiting the tip. Then it just gets washed down by the water. Also, it is spitting the exhaust out in a tighter shot, so it doesn't just swirl around under the swim step.
Yes, the moulded swim step is one of the reasons anyone ever sees this problem, since it gives a whole bunch of real estate for the soot to cling to! Nothing's free, I guess. The other enhancement to this is the fact that my exhaust tips are never near the water. Always several inches above.
Headers would definitely help. Anytime you add more velocity to the exhaust, it will get away from the gel quicker. Also, Teague had always suggested headers for 502s, since the scavenging would slightly lean the motor, making use of fuel that would otherwise be un-burned.
Yeah, rich is good.....to a point. The extra carbon just plugs up the cylinders (over years and years) and it is not good on the oil. Granted, if one changes oil like they should it's not in there long enough to do any real harm, but instead of mostly oil on the cylinder walls and piston skirts, you have a mix of unburned fuel and oil with each stroke. It mostly ends up in the pan.
Rockers would help a little also, since they add HP. Sure, it's just a little HP, but any additional HP needs fuel. One more way to use what's already there.
Maybe I will just pull the motor, put on the "Y" adapter, and shoot the exhaust thru the prop hub! (kidding)

[Beer-30]

Whipple Charged (Dustin) just PMd me and said they can re-cal for $795 and there would be the option to tweak the timing a little for some more HP, but would have to run 91. He said it would help the soot problem, but not eliminate it. Still going over my options. Looks like there will always be SOME.

[phebus]

Wax on, wax off grasshopper.

[Sane Asylum]

Wax on, wax off grasshopper.
You are so wise, OH great one........

[desertbird]

I just read through and caught up on some posts. Kachina sounds like a fart smeller, and he's right. We can complain all we like, but the bottom line is if the engine is operating withing parameters, that's it.
Here's a question. Instead of the run-around, why wouldn't Merc just make a statement regarding this? Call it normal operation, post it in an FAQ somewhere and put this to bed!
Someday (maybe this off season) I'm probably going to put the rollers, put some headers, and I might even pull the heads an shave a few thou to sneak up the compression ratio. We'll see.