Exhaust Riser Life Span

[FreeBeeTony]

What is the life expectancy of the exhaust risers?
My manifolds are FWC'd................just wondering how long the risers last.

Do they last longer than the raw water cooled manifolds?

Can I get an idea of their health from by removing the boot and looking at the "output" of the riser?

Is there any advantage going to the 4" riser from the 3"? Less restriction?

 

[Chris1956]

Re: Exhaust Riser Life Span

Tony, I have the 4" risers on my Mercruiser 4.3LX. I replaced he originals after 8 years or so, due to a hole on top of the "output" of the riser. I therefore recommend you look at that area, under the rubber boot. Luckily, the hole was "downstream" on the elbow, and no water got into the motor.

 

[Bondo]

Re: Exhaust Riser Life Span

Hi Tony,.......

As you know,... Up here in the Seawater Seas,...
Cast Iron Doesn't Rot out.....

If you check under the boot,+ find Chunks,.......
Remember, that Used to be Cast Iron........

I've also got the 4" risers on My 4.3LX,.......
I Don't Know if it's Any Advantage,....... I Do Know it Doesn't Hurt..........

Going SSteel will buy you considerable Time between replacements..........

Start searching ebay,..............They come by often,+ go Cheap....... Sometimes.........

 

[rojoc]

Re: Exhaust Riser Life Span

Hi Tony. I have an 88' 5.0L cobra. Boat was purchased from a neighbor so repairs and maintainance could be documented. The original raisers and manifolds were changed at 440hrs(15yrs.) The walls were extremly thin with lots of flaking. I would imagine that if they were not changed when they were I would have had salt water in the block. The engine was always flushed with fresh water after every use. Good luck.

 

[FreeBeeTony]

Re: Exhaust Riser Life Span

What part of the risers are stainless steel?

When I remove the boot can I tell if I have stainlesss?

 

[Don S]

Re: Exhaust Riser Life Span

Post a picture Tony. The Merc OEM risers and manifolds look nothiing like Stainless manifolds and risers. If you still have the same M&R's from when you first got that boat, you don't have stainless.

 

[FreeBeeTony]

Re: Exhaust Riser Life Span

Thanks Don..............haven't changed anything yet so I probably don't have stainless.

Probably going to pull it out of the water this w/e if the weather cooperates............

Not a bad season considering how it started!