It is time for manifolds and risers...

[Nick_L]

It is time for manifolds and risers on my 2--1- 310 with 7.4 I/O's. B3.  The marina head mechanic is suggestion that I cut off the  the water intakes via the drives and install 2 through hulls intakes with Great South Bay strainers. He claims the drives will restrict water flow from corrosion and they were never big enough on the year this drive was made.  The drives should stay cool from water circulating when under way or put drive showers in. He seems hot for me to do this...Or Merc has a kit to open them if if not to corroded and increase the opening to 1" or larger. .

Anyone ever do this?  Any feed back appreciated. 

[SRSD320]

The Mercruiser tech working our 2004 Sundancer 320 w/496 ci, 8.1L, 375 hp w/outdrives has pointed out the same Mercruiser outdrive water intake issue, and has done the 2 new through hull solution. The water pumps were also replaced as the boat's prior 165 hour life on a NV lake caused grit scoring inside the pumps, reducing their efficiency. We have the closed coolant system with heat exchangers cooled via raw water. The work appears to be effective, and hopefully eliminates the possibility the original narrow intakes have constricted, or may become constricted.

[Brite_Idea]

go for the thru hulls. The water still flows thru the drive so I don't think drive showers are necessary.

[thfoot]

I have a 2006 Sundancer 320 with 8.1L engines. 280 hours. Boat came from Lake Mead with 160 hours on it, but it's now in California Delta. Should I be thinking about cooling issues-mine shows no problems yet. Just made a 45 mi run down to the Golden Gate and held 4000 rpm or better all the way. All was good.

[SRSD320]

Re your post to SeaRay Owners Club, set out below.

I saw that boat and tested it Dec 2015. It was all good btw. I bought
the same boat, 2004; all identical also at Lake Mead: 160 hours etc,
etc.

I have had no real issues but diagnostics show likely overheat issue
rising as those outdrives have very small, narrow intakes. Solution is
in place now: new through hulls one for each engine to augment the
factory intakes. That should solve the issue. But, if problem is not
showing, maybe no reason to add those...

tim

I have a 2006 Sundancer 320 with 8.1L engines. 280 hours. Boat came
from Lake Mead with 160 hours on it, but it's now in California Delta.
Should I be thinking about cooling issues-mine shows no problems yet.
Just made a 45 mi run down to the Golden Gate and held 4000 rpm or
better all the way. All was good.

[thfoot]

Thanks for the info, Tim. I am going to pull it this winter and check the intakes while I have it out. I do notice my water pressure is slowly dropping (I have it up on the screen constantly) but I'm hoping that's just a function of the impellors wearing a bit. It sounds like a good fix that has been proposed. I run from brackish to salt to brackish then fresh, so I don't really know what kind of wear I should be experiencing. I put 100 hrs on it in the last year and it has treated me well so far.​

[Seabuz]

If you decide to do thru hulls, make sure they are NOT in line with the outdrives. They mess up the water flow. I have them they work well but my starboard engine cavates when planing. That's the one that the thru hull is inline with the outdrive. Once she's up on plane both engines equal at the same rpm.

[Korkie]

Had the same issue about half way into this season. Called Bravoitis. Installed thru hulls with T's to allow some water to still be pulled thru the drives. Started having cooling issues at higher RPMs along with the low water pressure. Water pressure now dead on, and temps at 160 no matter what the RPMs. I did install the drive showers as I had them on a previous boat and my drive fluid was not the burnt color after a season. Strongly recommend this. The marina that installed mine did it in 3 days and did an excellent job.