I'm eyeing a 2006 boat with a raw water cooled exhaust and I know what Mercruiser says about changing manifolds and risers

The boat is fresh water lake boat so do I have to change these parts now or leave them alone til I run it in the salt for a few years ???

Merry Christmas to everyone here !!!!!

Boating and summer time is my favorite

60 degrees here on Long Island today....... awesome !!!!

I am assuming it is a set of cast iron log exhaust manifolds and risers?

2006 Mercruiser apps used for all smallblocks and down were cast iron Dry joint manifolds and risers. The gasket inbetween the riser and manifold is very important for sealing even for the dry joint. These will be center location risers / manifolds - log manifolds and risers for Mercruiser were done away with in the early 80's just saying

496 Merc used Aluminum at first then switched - do not know what app you are looking at but they should be fine -

if someone has taken off risers you need to make sure new gaskets were installed and the correct gaskets installed as Merc has 3 different styles that can be confusing to some. Also make sure the gaskets were installed the correct way facing up and the correct position facing forward. I see this alot as some will install them in the incorrect positions especially the forward facing position they will have backwards, installed 180 incorrectly