Checking Risers

[ryanfr1]

2015 246SSI Bravo 3 Merc 5.7L operated in Salt Water. Boat was a 2015 leftover/demo purchased in spring 2016  with 7 hrs on the clock. Boat is on a lift out of the water when not in use.  Engine is operating normally, no temp spikes , no overheating and no apparent leaks on the outside of the risers or gaskets. I flush the engine religiously every time the boat is run with freshwater and then saltaway.

So the risers are 5 years old , had some salt water use in 2015 by dealer but most of the exposure to salt began in 2016  when I took delivery. I am thinking I need to take a look see and pull the risers after this season.   Appreciate any opinions on that or when you would  pull those risers for a look see based upon your experience /knowledge

[drewm3i]

I would pull and look...drain the manifolds first.

[Dgiles]

You can pull them if you want, but if you are flushing regularly I think you still have a little time before you need to. 3-4 years of use with regular flushing and saltaway is nothing. You should easily get another 5 years before you really need to check them.

[drewm3i]

3 hours ago, Dgiles said:

You can pull them if you want, but if you are flushing regularly I think you still have a little time before you need to. 3-4 years of use with regular flushing and saltaway is nothing. You should easily get another 5 years before you really need to check them.

You are probably correct, but can't hurt to look as long as they are reinstalled properly.

[Iggy]

I do have a closed system. But my 290 with twins is a 2011 model. Its been in salt since day one and it stays in the slip all reason. So far so good! So its now 8 years going on 9. So I think you can get a few more years out of it. I would wait before removing the manifolds at least two more maybe 3 years. If your going to remove them, than I would replace them.  

[Phillbo]

I would leave them alone for now and just monitor temps.....

[Wingnut]

Many things you run to failure, but not risers because you get no apparent warning. They will fail while underway, and as soon as you shut down whatever exhaust valves happen to be open will get a shot of sea water which lays in the cylinder. Next time you crank, you will experience a hydro-lock condition as you can't compress a liquid. Bent rods, broken ring lands, cracked exhaust valves, and dislodged valve seats are common. Best practice IMHO is to pull them after 6 seasons (conservative) and do a real world internal inspection with a bore scope. Clean them up, re-paint them, and install with new gaskets. Based on your observations then you can project when it will be a safe time to replace them, along with the manifolds and elbows. It varies so much depending on how the boat is run.  W

[ryanfr1]

Thanks for all the replies.

Most of the advice I am getting outside the forum including the my marine mechanic who knows me  and does service on the boat is they are likely ok this year. This is based upon his experience so this is going to be a year to year end of season decision with the clock ticking.   

[Water Dawg 6]

Concur with Wingnut, but usually 5-7 years is max for risers/manifolds with boat in the water all year long.  Monitor your temp, if you see your temp starting to get higher than normal that's usually the first sign that it's time to change them.  

[Wingnut]

I'm thinking Joe Average keeps a boat for around 10 years in the Northeast. So that said, if you pull and inspect at year 7, even if you have to change the manifolds, risers, and elbows you are good to year 14. Wait until year 8 and end up replacing the engine? I never understood why one would choose to kick this particular can down the road. Pull and inspect at year 6/7, and then you have a baseline. Gaskets are usually starting to leak and paint fails by then anyway, and I often find backed out manifold bolts in the bilge on boats I work on.  W