Riser Installation

Hi,
I am about to install my new riser. It is a brand new one. It has paint where the gasket goes...(they say it is to protect it from rust, and keep it preserved until it is sold)... Should I scrap off this paint off as it can cause problem sealing with the gasket?

I am not sure if that is a factory paint or no, I see no paint overlap etc.. but the riser also is painted from the inside....

It is a cast Iron riser used for a mercruiser 165 inline 6.

Thanks

Re: Riser Installation

Big flat mill file.
Take all that coating off.

Re: Riser Installation

bomar76 said:

Big flat mill file.
Take all that coating off.

Click to expand...

Thanks bomar.....I had a feeling that this need to done but I was not sure...
I am still on the learning curve.

Re: Riser Installation

bomar76 said:

Big flat mill file.
Take all that coating off.

Click to expand...

And here I am with a different opinion... Nowhere in the manual does it say to remove the paint. I leave the paint on. Since the paint adheres to the metal, and the gasket adheres to the paint I see no reason to remove it. In fact, I like to leave it on because it provides protection to the very edges of the elbow (and the manifold) so the rust can't start there and work its way in....

I'd love to hear evidence on either way....

Chris........

Re: Riser Installation

The only ones that I know of that want the paint off the manifold and riser are the newer Volvo's using the metal shim gasket.
Mercruiser doesn't use them so they say nothing about the paint and it's never been a problem.

Re: Riser Installation

Don S said:

The only ones that I know of that want the paint off the manifold and riser are the newer Volvo's using the metal shim gasket.
Mercruiser doesn't use them so they say nothing about the paint and it's never been a problem.

Click to expand...

Wow...I never would have expected that!
Vitually every other assembled engine item requires smooth clean bare metal sealing surfaces for the gaskets.

Re: Riser Installation

Now I am getting confused ... Indeed the manual does not mention anything about paint... But also some people say scrap the paint for better seal...


Don and Achris have a point that it will protect the riser for a longer time, as the metal is not exposed to heat and water which promote rust.

I am leaning to install it as is

Re: Riser Installation

I just found this in the Mercury / Mercruiser Service bulletin

which will answer my original question ... and take any doubt off my mind.


GASOLINE ENGINES AND WATER INTRUSION
Page 8 of 8 AUGUST 2001 2001-13
7. Repair.
a. Use a gasket scraper or a wide blade ?putty knife? to remove the old gasket. Do not
use a wire brush or sanding disk on a drill to clean the surfaces because the surfaces
will be rounded. Surface can be machined slightly to clean it up. See MerCruiser Service
Bulletin 99-10 for machining specifications. Look around exhaust passage for
discolored metal (dark in color). If the metal is dark after cleaning, replace the part.
b. Do not remove the paint from the gasket surface of new Mercury Parts exhaust components.This paint is a coating to help prevent corrosion. Sometimes a paint run or
a build-up of the ceramic coating is on the gasket surface of a replacement manifold,
riser or exhaust elbow. Use a file to remove just that defect. Leave the rest of the
surface painted.

Thank you everyone...