Engine ID and question about risers

[Woodman4]

Hey guys, newbie to the forum from North Carolina. Looking for some help with a boat I am looking to buy. This boat is several hours away from me, but appears to be in very good condition for its age. We are really wanting a v drive is the only reason I’m considering traveling so far (8 hours) for the right boat.

Anyways, the seller has had this boat for 6 years. He has done regular oil changes to it but says he’s never had to do anything else to it. He also isn’t sure which engine it has. Admittedly he doesn’t know much about engines and isn’t very mechanically inclined. So, I had him send me a picture of the engine hoping I could find some details. The boat is a 98 model and has 300ish hours. This is the original engine as far as we know. He thinks it is a 5.7 mercruiser, I assume it’s a carb motor. I’d just like to confirm that that is correct.

Also, I’ve been reading that the risers and manifolds are bad to rust and leak water into the engine. I’m curious if the rusty spots you see on each valve cover are indications of the risers going south?

If there is anything else you guys can tell me from the picture about the engine or anything that looks like it’s worn out please let me know.

Thanks

 

[Scott Danforth]

the rust you see is a non-painted machined surface. I would have a survey done and plan on new manifolds and risers soon.

only way to tell if a riser or manifold is bad is to pull it and inspect it.

 

[Woodman4]

the rust you see is a non-painted machined surface. I would have a survey done and plan on new manifolds and risers soon.

only way to tell if a riser or manifold is bad is to pull it and inspect it.

Thanks for the reply Scott. I'm trying to find someone to survey it now, I'm not sure how to know I've found a good one from so far away though!

 

[Scott Danforth]

simple, call the largest marina in the area, ask them

 

[Lou C]

Was the engine used in fresh or salt water? If fresh the manifolds and risers can last a long time, if in salt then they are a regular maintenance item, 5-7 year replacement is usually necessary to prevent water from leaking in to the center exhaust gas passage. Those look like the older style wet exhaust manifolds which really require close monitoring. The dry exhaust style that they started using in 2002 are better at not allowing water to leak in around that joint because the water passage and exhaust gas passage are separate not right next to each other.

 

[Woodman4]

Fresh water only as far as I know. I’m going to try to track down the previous owner because I believe he bought it new. Thanks for the info about the old style risers, didn’t know there was a difference. This boat is a 98 so you’re probably right.

 

[Scott Danforth]

if the boat is fresh water only, the manifolds and risers will last about 40 years (assuming proper winterization)