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  1. #1
    Join Date
    Aug 2010
    Location
    Newark, DE
    Boat
    Sea Ray
    Details
    2004 270 Sundeck
    Engine(s)
    6.2L MPI Bravo III
    Posts
    1

    Mercruiser 6.2L MPI issues!!

    Good evening all,

    This is my first post on here so please excuse my lack of knowledge. I need to mention I am mechanically inclined but fairly new to boat repairs.

    While coming in from a 45 minute cruise going about 3200 rpm the engine began to "jerk and sputter", resulting in sporatic acceleration and deceleration. I brought it down to idle and it seemed to run fine. When I attempted to speed up above 1500 rpm it would begin to sputter again. It also makes a knocking/clacking noise at higher rpms. I checked the gauges and everything is OK; temp, oil pressure, etc. Since I hadn't run it in about a month, I assumed condensation had built up in the fuel tank so I changed the fuel filter/separator and added Stable to the fuel. At idle it purrs like a kitten but as soon as I attempt to get on plane it knocks and sputters.

    Any assistance/guidance/suggestions is much appreciated. As I mentioned, I'm not boat engine savy so please excuse my ignorance.

    The boat is a 2004 Sea Ray 270 Sundeck with the 6.2L MPI with Bravo III outdrive. Up to this point I've never had any engine issues.

  2. #2
    Join Date
    Jun 2010
    Location
    Tampa Bay
    Boat
    Sea Ray
    Details
    270 SunDeck 2006
    Engine(s)
    377 Merc Bravo III
    Posts
    5

    Re: Mercruiser 6.2L MPI issues!!

    Sorry this is not a solution, but I'm experiencing an identical issue with the same motor in a 2006 270 SunDeck!

    My dealer suggested changing the fuel filter, so I'll do that tomorrow and let you know if it helps. Please post any answers you get.

    Thanks.
    mikemce

  3. #3
    Join Date
    Feb 2009
    Location
    Perry Hall , Md
    Boat
    Sea Ray
    Details
    2000 38 Sundancer
    Engine(s)
    7.4 Horizon FWC
    Posts
    115

    Re: Mercruiser 6.2L MPI issues!!

    Just a guess but it could be fouled plugs if you are lucky but most likely it's a fuel issue. I think your 6.2L has the fuel cooler unit (looks like a black lunch box attached to the side of the engine) on it and it has a low speed fuel pump, a high speed fuel pump along with a paper fuel filter cartridge. If so it could be a bad high speed fuel pump or a clogged filter. A lot of people tend to neglect this filter since it runs about $40 for the part. Somebody should jump in to verify this if I remember correctly. I just thought I would throw this out to give you something to check out.
    2000 38' Sundancer 7.4L Horizons (current)
    2004 39' Sundancer 8.1L Horizons

    2006 32' Sundancer 6.2L v-drives
    1991 35' Sundancer 7.4L v-drives
    1989 30' Weekender 5.7L inboard
    1988 27' Sundancer 5.7L I/O's

  4. #4
    Join Date
    Sep 2008
    Location
    Fort Mill, SC / Lake Wylie
    Boat
    Sea Ray
    Details
    2005 280DA, Lowrance HDS7, Windlass
    Engine(s)
    T-5.0 MPI Closed Cooling w/ Bravo Three Drives; Kohler 5E Genny
    Posts
    3,442

    Re: Mercruiser 6.2L MPI issues!!

    Quote Originally Posted by AAK View Post
    Just a guess but it could be fouled plugs if you are lucky but most likely it's a fuel issue. I think your 6.2L has the fuel cooler unit (looks like a black lunch box attached to the side of the engine) on it and it has a low speed fuel pump, a high speed fuel pump along with a paper fuel filter cartridge. If so it could be a bad high speed fuel pump or a clogged filter. A lot of people tend to neglect this filter since it runs about $40 for the part. Somebody should jump in to verify this if I remember correctly. I just thought I would throw this out to give you something to check out.
    If it is a Gen 3 Cool Fuel which I feel could be, (especially for the 2006 guy) there are actually two filters to worry about in the cool fuel unit if it is indeed the fuel filters causing your problem.

    See thread http://clubsearay.com/forum/showthre...highlight=cool for more info.

    If not you will have a Water Seperating (OIL Filter Style) Fuel Filter and a smaller inline filter. You will need to figure out which filter system you have.
    Last edited by jason78; 08-31-2010 at 07:30 PM.

    2005 Sea Ray 280 Sundancer
    Twin-5.0MPI Bravo III, Kohler 5E
    Other: 1997 Boston Whaler 20 Outrage, 200 Merc Offshore


    Previous Boats- 2003 Sea Ray 225 Weekender 5.0MPI Bravo III
    2004 Yahama XLT1200 Waverunner

  5. #5
    Join Date
    Jun 2010
    Location
    Tampa Bay
    Boat
    Sea Ray
    Details
    270 SunDeck 2006
    Engine(s)
    377 Merc Bravo III
    Posts
    5

    Re: Mercruiser 6.2L MPI issues!!

    Thanks to AAK and Jason78 (especially the link to the filter change instructions!).
    My 2007 270SD with the MX 6.2l MPI does have the GenIII cool fuel module. I changed both filters yesterday. Both were dirty with a little debris and noticible water. I was unable to take the boat out until this morning.
    After my 1+ mile of idle zone, I opened it up. It hesitated slightly, but came on strong. I ended up runnng around for about an hour; slowing down, then WOT, then 3000rpm cruise, etc.
    I think this is a fix.
    However, I'm getting some spare filters in case I have some water in my tank that could clog the filters again.
    Would it help to add Stabil to the gas? I've got about 50 gallons in an 85 gallon tank.

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