www.iFourWinns.com

I know this may have been discussed already, however I was wondering if anyone had any insight on replacing riser/manifolds on a Volvo Penta 5.7GS. I have a 2000 Vista 268 without a trailer and kept in salt water. My first choice would be to just have a mechanic replace them on the boat at my slip (even though I know there is a chance of water coming in through the disconneted exhaust). Has anyone ever had this done and how much did it cost? If not has anyone replaced the riser and manifold on their own with the boat in the water? Finally, any opinions on how often or signs for needing them changed. Thanks in advance for your input.

Pac Winn
268 Vista

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Pac Winn

First Boat:
2000 Vista 268

An easy job: I believe there's no chance of water coming in if you remove the manifolds and risers; they are (should be) higher than the water line. The manifolds are heavy, I'd suggest you use some dowels ( or bolts with the heads cut off) to locate the gaskets as the manifolds are replaced. Also, plug the exhaust ports when you remove the remnants of the gaskets.

Graham

I had mine done in the slip last summer. I have an 04 268 5.7 GXi. The temp on my motor crept up a few times last year to alarm point. I felt as though it was running about five degrees higher than normal so, being 6 years old, I had them changed by a buddy who is in the business. I took it to his marina and they did it in the water. Not much improvement on the temp, but plenty of peace of mind knowing it is done. My motor is FWC so my next step in the spring is to treat the heat exchanger with acid. It is possible that it is slowing the salt-water transition thereby allowing the anti-freeze temp to creep up a bit. Anyway, I gave him a thousand dollars because he was too busy to figure out the bill. I told him I would square with him when he figured it out. That was July. He still hasn't done it, but I would estimate it to be about a $1,500 dollar job if done by a private mechanic and not at a dealer.

I didn't replace, but I've had mine off in the water. Not a fun job, but not vey technical either. Graham has the right idea about using a guide for the gaskets, cuts back on the cuss words. On mine the water line was just below the top of the Y pipe.
Just a few helping thoughts, and I am by no means a mechanic.
1. WD40, spray it between metal and rubber to get things moving.
2. The manifolds are heavier than you think and smash fingers if your not paying attention.
3. Wait till your below 1/4 tank of gas, just helps to insure the waterline is lower than the riser pipe.
4. A couple of websites that I've ordered from, prices are great but shipping might sting a bit on manifolds. Marineengine.com, go2marine
It's really not that bad of job, about a 6 pak

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Lakebum
2006 378 Vista
Nashville, TN
Current
04 Hustler Cheetah
06 Seadoo sportster 150
Past
06 378 vista
328 vista
240 horizon
21' glastron
20' celebrity

Thanks for the advice! I may see what they want to replace them once I get my annual service completed.

Also, I notice a little bit of scale at the junction between the riser and manifold. The mechanic that looked the boat over when I bought it said was the beginning signs of leaks. He mentioned that I would have another year in his opinion before I needed to replace them. Any thoughts? I have heard of people re-torqueing the riser bolts from time to time as well to keep the seal tight between the riser and manifold, any one hear of this?

This is my first experience with saltwater boating so its all new to me. Thanks for your input.

Pac Winn
2000 Vista 268

_________________
Pac Winn

First Boat:
2000 Vista 268

It doesn't do any harm to retorque the bolts; the gaskets do creep with time.

That rust isn't necessarily from leakage, it may well be because the manifold flange face is not painted and the there are cutouts at the bottom of the risers in each corner, so that unprotected cast iron is exposed to damp air. Once I'd refitted the risers I gave those exposed areas a few coats of black paint.

Graham