Let's talk Exhaust

[RiskyinElsinore]

Ok guys what is the deal with the 496 Mag and the heavy exhaust build up on the transom?This is a new boat and it took me 409 detergent and a lot of rubbing to remove all the exhaust off the back of the boat after a day of play.Is there any good fix for this problem or do I have to just put up with it!! jawdrop

[riverliver]

Sounds like it's set up to run rich durring breakin period.

[Sleek-Jet]

There is a product called RejeX that is pretty new to the market.
It is a coating that keeps the exhaust from sticking to the surface.
I have used it on my airplane, and it works pretty good, keeps the lead from getting imbedded in the paint.
go to www.corrosionx.com (http://www.corrosionx.com) and there is a page for RejeX.
Good luck.

[rivercrazy]

Yup. They run very fat during break-in. The first 5 hours on my 496 HO were tough to clean up after. It has consistently subsided between 5 and the 25 hours. Now it barely smokes the transom.
Grin and bear it, continue breaking in the motor properly, and it will get much better.
The best way I've found to get it off is a cleaner/wax. It takes it right off. And it make the next clean up a lot easier.

[RiskyinElsinore]

So do you take the boat in and have ajusted or? :D

[RiskyinElsinore]

Cool so you think this is just a break in period? And no ajustments would be needed.Thanks for the help :confused:

[andy01]

From what I have read the 496 runs very rich for the first 10 hours of service then the computer will start to lien it out up to 30 hours and that is when it is tuned properly.
Andy

[BowTie Rick]

First, this is not a spam because most of you know where I work. The 496 like most boat motors runs rich. The rich condition helps keep the motor running cooler and also has some slight lubrication properties. Adding a K&N flame arrestor (part# 59-5005 for the 496) will lean it out just enough to get rid of most if not all of the soot but will not lean it out too much where you look like John Force at 1000 feet. Lean = speed but its hard on parts. Fear not, the computer will keep you from hurting anything. You may even pick up a few hundred RPMs. If I could figure out how to post an freakin' pic, I'd show you one installed. :confused:

[bordsmnj]

say, Bowtie? should i put one of those on my 6.2 when i get it ? do they make one for it?

[Waldo]

Ya, and do you guys make one for the 5.7 350 mag? If so, does it help any like you stated for the 496?
Thanks.

[RiskyinElsinore]

So tell me guys who on this board has the 496ho and has had this problem with the exhaust and has been cured with the K&N air filter or the computer leans down the fuel? :D

[BowTie Rick]

bordsmnj:
say, Bowtie? should i put one of those on my 6.2 when i get it ? do they make one for it? Ya, and do you guys make one for the 5.7 350 mag? If so, does it help any like you stated for the 496?
Actually both are in the works and should be available in April if all goes well with the R&D. The 6.2L and 350 Mag MPI both have the same throttle bodies. My question to you both is, which version do you have? There is a Mercruiser throttle body used until Sept. 2000 that has a 3 7/8" flange and a single stud in the middle. The latest use a GM throttle body that has a 3 5/8" flange and has 3 studs coming from the throttle body mounting bolts. We are doing both. If you would like to use your boat for a fit check as they get closer to completion, let me know. You get to keep the finished goods for the assistance.

[Waldo]

Sounds like a plan. I'll check the throttle body when I get home. I would assume it is the Mercruiser since my boat is a 2000 but will let you know soon. Thanks.

[bordsmnj]

sounds like a plan. :D But, are there any waranty issues that arise outa swapin' the filter??.If not than lets do it. i'll have the boat by around the third week of march if all goes as planned. it's being built by aftershock and is going to have a new 6.2 put in it so i'm thinking that it's gonna have the GM size throttle body.PM if yuh have any questions or what ever.
thankyou-jason