Seacore comes standard with a fresh water flush?

Discussion in 'General Discussion' started by Nick70, Dec 28, 2017.

  1. Nick70

    Nick70 Member

    107
    Apr 20, 2016
    New England
    2009 Sea Ray Sundancer 330/350
    Twin 496's
    BRAVO III Sea core
    Garmin radar/gps
    8.1L's w/Bravo III Sea Core
    Im about to buy a 2009 330 with the 496/Bravo III setup.
    The dealer said they ran the serial numbers and confirmed they are Seacore.
    However, when I asked a while back if the engines had a freshwater flush kit, the answer was 'no'.
    I just watched a Mercruiser video and in it, they mentioned the freshwater flush kit came as part of the Seacore package. So, I'll contact the dealer and ask for clarity.
    In the meantime, any info anyone may have would be greatly appreciated.
    May save us airfare on the trip to check it out next week.
     
  2. Jmac572

    Jmac572 Member

    107
    Dec 20, 2016
    Plymouth, MA
    "Freedom"
    2017 Sea Ray 290 SDX
    Twin 225 Verado Outboards
    I had twin 350 Mag MPI sea core on my last boat so i'm familiar with the setup... Im 99% sure that if your 496 motors are true sea core then they will not have a fresh water flush. Having a fresh water flush on a sea core motor just doesn't make sense as its a full fresh water system. The only thing salt water will come in contact with is the raw water pump, heat exchanger, and exhaust elbows. Everything else has coolant running through it, even the exhaust manifolds and risers (which means you're virtually eliminating the need to ever replace your manifolds and risers again).

    Now I believe if the 496 motors have a standard fresh water cooling system (i.e. half fresh water cooling) then salt water would be running through the manifolds and risers, requiring them to be flushed out every so often.

    The only thing I can think of that you may be referring to are all the "blue" caps on the engine and heat exchanger where you use the provided hand air pump and force out all the raw water at the end of the season to winterize the boat. And there mayyyy be a spot to connect a hose to the heat exchanger and flush it out but I dont really recall that.
     
  3. mnm99

    mnm99 Well-Known Member SILVER Sponsor

    Oct 2, 2015
    Long Island
    2004 340 SeaRay Sundancer
    Twin 8.1 Merc
    No fresh flush on that motor. It has a purge system. That's what the pump is for.
     
  4. Spark600

    Spark600 New Member

    15
    Dec 28, 2013
    Long Island NY
    29' Amber jack with twin 5.7 Mercruiser and V drives transmission
    Kohler Generator
    Mercury dinghy
    29' Amber jack with twin 5.7 Mercruiser and V drives transmission
    I have 2008 twin 496 /Bravo III sea core setup with fresh water flush, but it does not work because all they did is put a T in the hose from the drive to the sea pump so when you try to flush the system it pulls sea water and fresh water at the same time as there is no way to turn the water off from coming in the drives.
    I called Mercruiser and they said that the sea water goes through the manifolds and risers because the 496 produce way to much heat in the exhaust to run the antifreeze ( fresh water cooling ) through them.
    If the boat is out of the water the fresh water flush might work.
    I added sea strainers in the boat and when i re plumbed the sea water hoses for the new strainers I removed the fresh water flush hose as it never worked.
    As Mercruiser recommends changing the exhaust manifolds every 10 years on that motor I just changed my about three weeks ago and there is definitely sea water in the exhaust manifolds not antifreeze.
    You do not have to change the exhaust elbow as they are stainless steel.
    I did purchase a 33' boat with 496 and no longer have the 5.7
     
    Last edited: Dec 30, 2017
  5. mnm99

    mnm99 Well-Known Member SILVER Sponsor

    Oct 2, 2015
    Long Island
    2004 340 SeaRay Sundancer
    Twin 8.1 Merc
    You may be wrong about this one. I did a bunch of tests with a hydrometer flushing my system and I was pretty amazed what I found. I put a TEE between my water pickup and strainer also. I went out and bought a hydrometer to measure the salt content coming out my exhaust. ( you can't check the bravo 3 like I can ) When I checked the salt content it was right on where it needed to be. When I turned on the hose to the TEE and ran the motor WITH the seacock open I did another test 3 min later. The Hydrometer read ZERO. I did this 3 times, because I thought it wasn't right. Every time it cam up as zero...The water pressure must overcome the pump pressure. My pumps pull some crazy water also...Next season I'm installing a TEE along with my salt away flush. You can see the hydrometer is sitting on my swim platform..NO BS here..
    BEFORE FLUSH thumbnail (6).jpg
    AFTER FLUSH..
    thumbnail (8).jpg
    thumbnail (7).jpg
     
    Last edited: Dec 30, 2017
  6. Spark600

    Spark600 New Member

    15
    Dec 28, 2013
    Long Island NY
    29' Amber jack with twin 5.7 Mercruiser and V drives transmission
    Kohler Generator
    Mercury dinghy
    29' Amber jack with twin 5.7 Mercruiser and V drives transmission
    MerCruiser told me it does not work.
    From the picture look like you have inboard and not drives, does that make a difference ??
     
  7. mnm99

    mnm99 Well-Known Member SILVER Sponsor

    Oct 2, 2015
    Long Island
    2004 340 SeaRay Sundancer
    Twin 8.1 Merc
    Has that tech you talked to ever experimented? Prob not..They can't tell you it works. I have solid proof with results.
    I can't see why it would make a difference. Your pump is still on the motor. The pickup just comes from the drive , not the bottom of the boat. You can't verify since you exhaust water comes out of the drive and transom. I guess you can do the same test and pull the hose on the exhaust manifold after a few min and test it with a hydrometer like I did ( after shutting down the motor). That would verify clean salt free water too.
    I want to note also..I can keep the fresh water running with the engine OFF and it will NOT fill the motor with water. It drains out the seacock and doesn't make it up to the trans cooler.
     
    Last edited: Dec 31, 2017
  8. Nick70

    Nick70 Member

    107
    Apr 20, 2016
    New England
    2009 Sea Ray Sundancer 330/350
    Twin 496's
    BRAVO III Sea core
    Garmin radar/gps
    8.1L's w/Bravo III Sea Core
    The plot thickens...
     

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