Go Back  Offshoreonly.com > General Discussion > General Boating Discussion
496 mag  CARBON BUILD UP ON TRANSM >

496 mag CARBON BUILD UP ON TRANSM

Like Tree0Likes

496 mag CARBON BUILD UP ON TRANSM

Reply

Old 06-03-2002, 06:23 PM
  #1
Registered
Thread Starter
 
Join Date: May 2002
My Boat: 2001 33 Baja Outlaw
Posts: 6
Default 496 mag CARBON BUILD UP ON TRANSM

[[email protected]]

Hey Guys, Any feedback re: excessive carbon build up on transoms on these new 496's. Mercury rep seems to think thats normal. DONT KNOW WHAT HE'S THINKING!!!!!!!!

I HAVE GOT 72 HRS. AND IT IS STILL THE SAME SINCE DAY ONE.

WHEN DOES IT GET BETTER?

ANY CHIP PROGRAMMERS OU THERE?

THX. GREGG

Last edited by 33outlaw; 06-04-2002 at 08:58 PM.
33outlaw is offline  
Reply With Quote
Old 06-03-2002, 06:47 PM
  #2
Registered
 
Join Date: Oct 2000
Posts: 1,238
Default

Believe it or not......it is normal. Merc runs their motors real rich...so we don't blow them up as quick and it helps run the motor cooler. Also the type of gas can contribute to it somewhat. I bought a set of computers and had a shop set up a different program....that helped the carbon problem (about 85-90%) and helped the performance of the boat
enticer is offline  
Reply With Quote
Old 06-03-2002, 07:05 PM
  #3
Registered
Thread Starter
 
Join Date: May 2002
My Boat: 2001 33 Baja Outlaw
Posts: 6
Default

Originally posted by enticer
Believe it or not......it is normal. Merc runs their motors real rich...so we don't blow them up as quick and it helps run the motor cooler. Also the type of gas can contribute to it somewhat. I bought a set of computers and had a shop set up a different program....that helped the carbon problem (about 85-90%) and helped the performance of the boat

HEY THANKS FOR THE REPLY
I HAVE BEEN ONLY USING 87 OCTANE AND NO OTHER REVISIONS
DID YOU HAVE YOUR CHIPS REPROGRAMMED? OR BOUGHT ALL NEW? AND WHERE?
33outlaw is offline  
Reply With Quote
Old 06-03-2002, 07:56 PM
  #4
Registered
 
Join Date: Sep 2001
Location: Lakeway, TX (Austin/Lake Travis) / LOTO Gravois Arm
My Boat: 2002 Nordic 28 Heat / 2013 Bass Cat Puma FTD
Posts: 671
Default

Chiming in...

I've also heard it's normal. I had reasonable build-up the first 25 hours on mine. Seems to be dissipating. 87 octane only is the right approach.

Also, just replaced stock flame arrestor with a K&N this weekend. I've heard that this swap helps with carbon -- but too soon to tell definitively. Sounds good, though.

dh
In2Deep is offline  
Reply With Quote
Old 06-03-2002, 09:40 PM
  #5
Registered
 
Macklin's Avatar
 
Join Date: Dec 2001
Location: Virginia Beach
My Boat: 36 Concept w/ Merc 250 EFI Smokers
Posts: 1,907
Default

Yup.....same here. I had it real bad for the first 25 hours or so. Since then I have seen very little build up.
Macklin is offline  
Reply With Quote
Old 06-04-2002, 08:30 AM
  #6
Platinum Member
Platinum Member
 
CigDaze's Avatar
 
Join Date: Jun 2001
Location: St. Petersburg, FL
My Boat: Cigarette 35 Cafe Racer
Posts: 21,346
Default

It's normal.

It had me worried for a while as well, until I asked my High-performance Merc expert about it. He said no problem, just live with it. The first 25 or so hours were the worst, but it has gotten better since then.

I just spray some Simple green on the transom after each day out(or weekend) and it comes right off very easily. Good wax also helps.

The crappy thing is that my swim platform also gets it pretty bad from the wind vortices...makes for some pretty dirty knees and hands from swimming.

---------------------

Here's one for you guys...Mine seems to be much dirtier on the port side. Is this what you guys are seeing? I heard it's got something to do with the way the cooling water is plummed through the exhaust...
CigDaze is offline  
Reply With Quote
Old 06-04-2002, 10:15 AM
  #7
AZDominator
Guest
 
Posts: n/a
Default

Same here, I have 2 496 Mag HO's. First 20-30 hrs build-up was bad, particularly above 4000 RPM. Between 2500-3500 I would get very little. Now I have 70 hrs on them and I get very little residue.
 
Reply With Quote
Old 06-04-2002, 10:36 AM
  #8
Registered
 
teckersley's Avatar
 
Join Date: Jul 2001
Location: Houston,Tx.
My Boat: 2002 Fountain 27'
Posts: 57
Default

My $0.02

Same problem. The first 25-30 hours was terrible but the more hours I put on it, the better it gets. I just keep a small spray bottle of simple green in the boat for cleaning while swimming. Otherwise, this s%#t gets everywhere.
teckersley is offline  
Reply With Quote
Old 06-04-2002, 01:01 PM
  #9
Registered
 
Racing_Fan's Avatar
 
Join Date: Mar 2002
Location: Alexandria, VA
My Boat: 2004,Formula,292 FasTech
Posts: 64
Default

Baja Daze,

The port side on my boat has been dirtier than the starboard since my 10+ hour mark. My transom was extremely dirty from 0-15 hours, and it has lightened up a bit lately. I'm wondering too if the port side sees more soot because of the cooling water plumbing...

---------------------------------

For all you 496'ers with single-point air drain systems, be careful at the start of the day after you release the pressure from the system...I throttled up one day and cruised for 2-3 minutes and then found a bilge full of water and a very hot port exhaust header. It seems the system still had some slight pressure in it and part of my cooling water was leaking into the bilge thru the drain gate on the port side.

-Racing_Fan
Racing_Fan is offline  
Reply With Quote
Old 06-04-2002, 01:50 PM
  #10
Platinum Member
Platinum Member
 
CigDaze's Avatar
 
Join Date: Jun 2001
Location: St. Petersburg, FL
My Boat: Cigarette 35 Cafe Racer
Posts: 21,346
Default

Thanks for the tip Racing_Fan!
CigDaze is offline  
Reply With Quote

Quick Reply: 496 mag CARBON BUILD UP ON TRANSM


OSO Sponsor
OSO Advertiser
OSO Advertiser
OSO Advertiser