Tell me more about Merc 4.3L one-piece exhaust risers

[garycinn]

All this talk about manifolds and risers has got me thinking .<br /><br />I have these one piece Merc units. I was wondering how they hold up in real life. Are they better or worse than the two piece? If/when I have to replace them, do I have to use the same 1-piece? I ask because they are crazily expensive (~$600 a side).<br /><br />I also have EFI bracket that screws into the 1-piece riser. If I went with 2-piece, I would have to rig something to mount this EFI equipment.<br /><br />Since mine is a '01 with 185 hours, what kind of life would you expect out of these 1-piece units? Fresh water only, raw water cooled.

 

[Don S]

Re: Tell me more about Merc 4.3L one-piece exhaust risers

Since most of the problems with leaking risers and manifolds come from the joint between the two, the one piece manifold eliminates that problem. When the finally do plug up due to rust and corrosion (and they will) they would need to be replaced.<br />Yes, you probably could replace them with the 2 piece style, but you would have to install the parts 1 through 5 too. They aren't needed with the 1 piece style.<br /><br />