Manifold/Risers in the northeast

Discussion in 'Northeast' started by Strecker25, Nov 2, 2017.

  1. Strecker25

    Strecker25 Well-Known Member SILVER Sponsor

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    Hi guys, going through a search for our next boat and have a question regarding the exhaust schedules on boats used in the NE. There are many good looking examples in the CT, NY, NJ area.

    I know in the southern brine people replace manifolds/risers every 3-5 years. Does that schedule hold up in the NE even when the boat is pulled for the winters? I can't find a definitive answer as to whether the colder water and shorter season have much of an affect.

    Obviously this will vary boat to boat, just looking for a general idea so I can factor the parts into the cost before getting serious about anything.
     
  2. SloBurn

    SloBurn Member

    764
    May 30, 2013
    Greenwood Lake, NY
    1994 270 Sundancer. 7.4L Merc. Tow with a 2006 Dodge RAM Hemi
    340 HP Merc 454 c.i.
    If you're in the salt, I would replace every 5-7 years or so, depending upon use. Fresh water, every 10-12.
     
  3. Ididntdoit

    Ididntdoit Well-Known Member

    Dec 5, 2007
    East Coast Florida
    300 Sundancer
    5.0MPI Bravo III
    I replaced mine after 7 seasons in salt water year round (Newport Harbor RI) and they looked excellent - could Hardley justify replacing/scrapping them - they were dry joint and that eliminates the most troublesome area.....
     
  4. paulswagelock

    paulswagelock Well-Known Member

    Oct 25, 2010
    pa
    2018 SDX 270 OB 300 Verado
    Verado 300
    300 hours or so for salt water users seems typical, which works out to 6-7 years in most areas of the country where year round boat weather does not exist. Being a fresh water boat user for 30 years now, I have never heard of anyone in my area ever replace manifolds.
     
  5. Strecker25

    Strecker25 Well-Known Member SILVER Sponsor

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    Thanks guys, We’re looking are 1999-2002 340s with a preference to the 8.1s so they would have the SS elbows. My concern with that motor would be that the aluminum manifold has been swapped for cast, and how long ago.

    The earlier boats have the 7.4 or early 8.1 with cast exhaust. Many of the cleaner boats have had the exhaust done within the last 3-4 years.

    We would be bringing it up to Lake Ontario so I’ll try to find one with a relatively recent exhaust job and they should last a while in the fresh water.
     
  6. JVM225

    JVM225 Well-Known Member

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    5 years on OEM stuff here on Long Island. Less for aftermarket parts.
     
  7. Gary B

    Gary B Member

    152
    May 20, 2015
    Long Island
    2007 52 Sedan Bridge
    Cummins QSM 11
    In addition to the exhaust on the 8.1 you may also have to replace the transmission cooler and some 8.1's also have fuel coolers. These coolers have salt water running through them and they corrode just like the exhaust.
    You should also know that in addition to salt water corrosion on the fuel coolers Mercury has had problems with ethanol and the fuel coolers. The coolers are painted by Mercury on the inside and the ethanol in the gasoline eats off the paint which in turn works it way down the fuel system towards the injectors. This can cause big problems. Ethanol issues are not unique to Mercury but one could argue that the fuel coolers should not be painted internally.
     
  8. Strecker25

    Strecker25 Well-Known Member SILVER Sponsor

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    Thanks, I've read about the fuel cooler woes but the tranny cooler never crossed my mind.
     
  9. Ididntdoit

    Ididntdoit Well-Known Member

    Dec 5, 2007
    East Coast Florida
    300 Sundancer
    5.0MPI Bravo III
    He's looking at earlier boats - that problem did not start until '05 with the into of cool fuel III
     
  10. rondds

    rondds Well-Known Member SILVER Sponsor

    Oct 3, 2006
    Jersey Shore
    2001 380DA
    Merc 8.1s (2008)...Hurth ZF 63 V-drives...WB 7.0 BCGD (2013), Garmin 8208 & 740 MFDs, GMR 24xHD dome
    Don't forget the heat exchanger and the crankcase oil cooler. All these things have finite lifespans in salt water since they all have raw water running through them. They all need to be included in the "routine maintenance" regimen.
     
  11. Strecker25

    Strecker25 Well-Known Member SILVER Sponsor

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    I'd need a second job to boat where you guys do ;) Thanks for the info, I'll keep all of this in mind while we browse boats
     
  12. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Heat exchangers and coolers with the exception of the CF3 are made of brass and have a considerably longer life span than iron or aluminum
     
  13. SteveRuss

    SteveRuss Member

    161
    Jan 25, 2011
    Amityville, New York
    2000 280 Sunsport
    Twin 5.7L EFI w/Bravo I Drives
    Cheaper to change early than after you scuttled a motor. Start checking seasonally after 3 years with a hard replace at 5 regardless.
     
  14. Boston-boater

    Boston-boater Member

    132
    Oct 29, 2013
    Marion/Massachusetts
    2000 310 DA
    350 Horizons v drive
    I did not know about trans coolers until one failed. Fortunately caught it in time before trans damage. Replaced both trans coolers, oil coolers, risers and spacers. Ouch!
     

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