Opinion on risers and manifolds (Pics)

[AS19-1]

These are the manifolds and risers off my 2001 5.7 Marine Power. It appears to me that these are ok but would like some more opinions. I sandblasted them lightly with glass beads. Thanks.

 

[Alpheus]

Re: Opinion on risers and manifolds (Pics)

It appears to me that these are ok

You cant tell by looking.

Are they used in salt water or fresh?

Why did you take them off?

Read this...

http://forums.iboats.com/showthread.php?t=288629

 

[AS19-1]

Re: Opinion on risers and manifolds (Pics)

Saltwater use. I took them off because I ran through some mud and one riser was hot. Thanks for the link.

 

[Lou C]

Re: Opinion on risers and manifolds (Pics)

I'd replace em because the surface between the exhaust passage and water passage is getting thin in spots...

 

[scoflaw]

Re: Opinion on risers and manifolds (Pics)

If you can't tell by looking then where do they fail? Why can't OP resurface the gasket areas?

 

[AS19-1]

Re: Opinion on risers and manifolds (Pics)

Did not have any sealing problems before or any leaks into exhaust. Just ran through some mud and one riser got hot. Decided to pull them both to clean up. This is my first I/O always had outboards. I think the walls still look plenty thick. Plan on reusing maybe change out next year.

 

[Alpheus]

Re: Opinion on risers and manifolds (Pics)

You cant tell just by looking at them. You need to change them. Salt water manifolds and risers should be changed every 4-5 years. You are tempting fate by using 9 Y/O parts. Spend a little money now or you could be buying a new engine in the near future...

You said this is your first I/O so please listen to the advise given. We are not here to try and make you buy parts you don't need. Just do a search and read the horror stories on here about how people destroyed their engines because of manifold/riser failures. 99% of the people that tell the stories say the same thing. "I was going to replace after this season."

 

[scoflaw]

Re: Opinion on risers and manifolds (Pics)

Still lookin for a more detailed explaination on the weak area of a riser.

 

[AS19-1]

Re: Opinion on risers and manifolds (Pics)

How many hours are they rated for. Thanks

 

[AS19-1]

Re: Opinion on risers and manifolds (Pics)

Are you suggesting changing manifolds also. I bought this boat(formula 233) with the 2001 marine power from an old man who repowered but then only put 150 hours on it before it sat for many years. I would say the engine has only around 300 hours.

 

[Alpheus]

Re: Opinion on risers and manifolds (Pics)

There is no specific area that they all rust out at. If you run in salt water replace them every 4-5 years. Some people change them every 2-3 years. Salt water and cast iron are not the best of friends. Cast iron rusts.peals off and rusts some more. The cycle continues until it leaks, then you start a new post:

"Water in my engine now what" or "Water in my cylinders"

 

[Lou C]

Re: Opinion on risers and manifolds (Pics)

I copied one of these pix and outlined the sealing surface in red. You can see how narrow it is getting and keep in mind the ability of the gasket to keep water out of the exhaust passage depends on this sealing surface. If you get salt water in that exhaust passage it can go rightr in to a cylinder or rust exhaust valve stems.....