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  1. exhaust manifold cracked

    I have a 1992 200 overnighter with a 4.3 V-6 Alpha. while cleaning I noticed a crack in the side of the port side manifold near the bottom. Its not leaking very bad but it is leaking. Should I replace them both including the exhaust elbow or just wait till it gets worse. What should I check for when I remove it. Thanks for any info.
    Chris
    1992 SeaRay 200 Limited 20'
    Mercruiser 4.3 V6 Alpha One

  2. #2
    Join Date
    May 2008
    Location
    Thousand Islands, Rockport, Ontario.
    Boat
    Sea Ray
    Details
    1988 390 EC
    Engine(s)
    454 Mercruiser Gassers
    Posts
    2,278

    Re: exhaust manifold cracked

    How big of a crack is this? Is it feasible to take it off & have it welded?

    ~ Ken

    1988 390 Sea Ray EC
    Twin 7.4 l. Gassers
    6.5 KW Onan Gen.
    1,000 Islands
    Rockport, Ontario, Canada

  3. #3
    Join Date
    Oct 2006
    Location
    Oakland, NJ
    Boat
    Sea Ray
    Details
    1998 330 DA E80 GPS, Radar, & heading sensor
    Engine(s)
    7.4 Mag. Horizons 380hp
    Posts
    1,093

    Re: exhaust manifold cracked

    I don't know were your boat is located, so I don't know if you winterized your boat for the winter. If this was because the engine wasn't properly winterized there may be other areas of the engine you should be checking as well. I havn't seen to many cast manifolds crack that wasn't caused by freezing. You have to change at least the manifold in question. It is less expensive to just change the manifold then find someone to weld cast (not easy).
    Larry

    1998 330 Sundancer "Miss Melina"
    2 X 7.4 Mag. Horizons 380hp FWC
    Ryamarine E80 GPS, Radar, & heading sensor
    Home Port: Norwalk Cove Marina, Norwalk CT

  4. #4
    Join Date
    Nov 2006
    Location
    Northern NJ
    Boat
    Uhh. Lets see now this is Club Sea Ray. Right?
    Details
    1999 Sea Ray 330DA Twin 7.4 MPI (310 propshaft HP) V-drives All standard equipment including: Can
    Engine(s)
    Twin Mercury Marine marinized 7.4L L-29 V8s Cast iron block w 4-bolt mains 4.25x4.00 bore & strok
    Posts
    5,253

    Re: exhaust manifold cracked

    Replace them. If they are also leaking internally, then water can get into the exhaust ports. If that happens, you'll learn about penny wise and pound foolish.

  5. Re: exhaust manifold cracked

    Thanks for the info. The boat was kept in NJ. Since I just bought I don't know if it was winterized. Probably should have asked. The crack is about 3" long. I think I am just gonna bite the bullet and change them both.
    Chris
    1992 SeaRay 200 Limited 20'
    Mercruiser 4.3 V6 Alpha One

  6. #6
    Join Date
    Nov 2006
    Location
    Northern NJ
    Boat
    Uhh. Lets see now this is Club Sea Ray. Right?
    Details
    1999 Sea Ray 330DA Twin 7.4 MPI (310 propshaft HP) V-drives All standard equipment including: Can
    Engine(s)
    Twin Mercury Marine marinized 7.4L L-29 V8s Cast iron block w 4-bolt mains 4.25x4.00 bore & strok
    Posts
    5,253

    Re: exhaust manifold cracked

    If the engine was not winterized, considering the winter we just experienced, that block might be cracked as well

  7. #7
    Join Date
    Nov 2008
    Location
    Saugatuck, MI
    Boat
    Sea Ray
    Details
    1985 270 Sundancer
    Engine(s)
    3.7 liter Mercruisers
    Posts
    902

    Re: exhaust manifold cracked

    Quote Originally Posted by fc3 View Post
    Replace them. If they are also leaking internally, then water can get into the exhaust ports. If that happens, you'll learn about penny wise and pound foolish.
    +1

    Mine cracked internally and had i not checked the cylinders for coolant and gotten it out right away I would have needed a new engine as well as manifold.

    Eric Smith
    1985 270 Sundancer, 170 mercruisers
    340 acti-v west marine inflatable, old Honda 10hp
    Previous boats: 16' starcraft, 16' four winns, 23' searay weekender

  8. #8
    Join Date
    Oct 2008
    Location
    Southern MD/ Potomac river
    Boat
    SeaRay
    Details
    1989 340 EC
    Engine(s)
    7.4LX2 Hurth 630A Drives 6.5Kw QS Genny
    Posts
    945

    Re: exhaust manifold cracked

    Quote Originally Posted by Chriswaxx View Post
    I have a 1992 200 overnighter with a 4.3 V-6 Alpha. while cleaning I noticed a crack in the side of the port side manifold near the bottom. Its not leaking very bad but it is leaking. Should I replace them both including the exhaust elbow or just wait till it gets worse. What should I check for when I remove it. Thanks for any info.
    Replace them both. I messed around with mine on my small boat and ended up replacing the motor. Which had a bad crank bearing and I ended up sending it back and putting in a second motor. A year earlier probably would have saved me close to $2500- 3K

    1989 Sea Ray 340EC
    2X 454BB 6.5Kw QS Gen
    Hurth 630A straight drives

  9. #9
    Join Date
    Oct 2006
    Location
    Oakland, NJ
    Boat
    Sea Ray
    Details
    1998 330 DA E80 GPS, Radar, & heading sensor
    Engine(s)
    7.4 Mag. Horizons 380hp
    Posts
    1,093

    Re: exhaust manifold cracked

    I hope you got a good deal, because this could get expensive. Before you even start with the manifolds I would check the integrity of the block, because I would be very suspiciuos of an issue with that.

    Sorry, not to sound negative but I would be surprised that all that cracked was the manifold.
    Larry

    1998 330 Sundancer "Miss Melina"
    2 X 7.4 Mag. Horizons 380hp FWC
    Ryamarine E80 GPS, Radar, & heading sensor
    Home Port: Norwalk Cove Marina, Norwalk CT

  10. #10
    Join Date
    May 2008
    Location
    Knoxville TN
    Boat
    Sea Ray
    Details
    2000 SeaRay Sundancer 270
    Engine(s)
    7.4l Mercruiser w/ Bravo III
    Posts
    1,012

    Re: exhaust manifold cracked

    Unfortunately, I have done this before. I used to winterize the boat by draining all the water (not by filling with antifreeze). One year I forgot to drain one manifold. I drained the block, the pumps, and the other manifold. I just forgot one.

    A winter of freezing weather later, I had a cracked manifold. I believe I paid $250 for the manifold and gasket, not too bad to reinstall. Hopefully that is all you've got as well but be sure to check everything else.

    John
    2000 Sea Ray 270, 7.4L Mercruiser Bravo 3
    1995 Cobalt 200, 5.0L Volvo Duoprop
    Fort Loudoun Lake, Knoxville, TN


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