260DA 6.2 overheating

Discussion in 'Gas Engines/Drives/Transmissions/Props' started by Happy Dayz, Nov 22, 2017.

  1. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    so our new to us 260 overheated this past weekend. alarmed, shut her down, let cool, fired up and cooled quick...

    bought a thermostat and new impeller... hopefully get out of work soon to dig in..

    any other thoughts or places to check?
     
  2. CliffA

    CliffA Well-Known Member GOLD Sponsor

    Dec 29, 2009
    Lake Norman, NC
    2001 Sea Ray 340DA
    Name: 'Happy Place'
    4.5kW West. Generator
    Purchased Nov. 2014
    Fresh Water Use
    Twin Merc. 6.2L (MPI)
    Raw Water Cooled
    V-Drive Transmissions
    chances are good either the new impeller or t'stat will solve the issue.....

    if not post back and we should be able to help you track down the problem with additional troubleshooting suggestions....

    cliff
     
  3. JimG

    JimG Active Member SILVER Sponsor

    Nov 4, 2008
    Southern WV
    2007 310 DA
    Kohler 5ECD
    Twin 350 Mags
    Raw Water Cooled
    V-Drives
    What outdrive do you have (you need to list it and your engine in your profile)?
     
  4. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Give that brass pump a good look over, it scores easily. While its out backflush from the power steering cooler towards the pump, could be some impeller parts caught up there from a PO's overheat, even if your impeller is intact. assuming it's a Bravo
     
  5. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    You mentioned that it cooled down quickly after you restarted. Are you also saying it ran fine afterwards? You might not need to do anything - you may have just had some debris/weeds over the intake. For piece of mind, you can check the impeller and housing, but honestly, if it is running well now I'd probably leave well enough alone. Now, if there's a concern that the impeller ran for a bit without ANY water to it, then I'd definitely change it for piece of mind. But most likely there was some water running to it - and if it ran fine afterwards...
     
  6. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    good morning and Happy Thanksgiving

    forgot to add after i shut her down to cool off.. we idled for awhile and was cool but picked her up again and temp ticked up till overheat again..

    ...shes a 06 6.2 MPI w/ Bravo III drive..

    i dug in:

    found the water distribution unit where the thermostat is to be in rough shape with rust and black gunk.. one port to riser half clogged... had to destroy the plastic thermostat sleeve to get thermostat out.. a lot of built up crud..

    main hoses most had crust formed inside, as i grabbed, it crackled and broke up..

    one smaller hose, drain from headers was packed for about 6" of sea crud..

    pulled the impeller and was fine..

    So I have done:

    reamed out and cleaned distribution unit best I could.. prepped for new thermostat but have to find a new sleeve...

    replaced impeller with new since i was in there..

    pulled all crunch hoses, wringed them around to break up crust and flushed out.. cleared small blocked hose..


    the manifolds, risers and elbows were replaced 2 yrs ago and from the outside look in good shape...

    So.... should i go further and pull the headers, etc?

    Thanks everyone!

    here are some pics...

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  7. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Definitely looks neglected, I'd pull a riser off, water pump looks scored and probably a prime candidate for bravoitis as well. That small hose going to your manifold is the feed not a drain. Those 2 small hoses that go to your manifolds are the only route for water to exit the system.
     
    Last edited: Nov 23, 2017
  8. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    ...i hear ya scoflaw... fortunately the Bravo was just rebuilt.
     
  9. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Bravoitis takes place in the transom assembly and is not visible unless you disassemble. I wouldn't sweat that yet.
    Your overheat was probably caused by that plugged manifold hose.
     
  10. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    What Scof is talking about, though, is not so much the drive itself. It's the water tube that goes through the transom. There's a new design out there - just in case whomever recently worked on it didn't do that.

    Yeah, that looks YUMMY! :p

    -- Pull at least the elbows/risers off and take a look at things. Depending on what you see, then decide on whether or not to pull the manifolds.
    -- Remove the hoses and the fittings under each manifold and on each side of the block, looking for buildup there. Draining water out via the quick drain thing is not a substitute for this.
    -- This looks like a candidate for a complete engine flush with muriatic acid.
    -- Be sure to completely flush the t-stat housing, too.
    -- Before you go too far... stick your hand and/or cell phone under the engine and check out the oil pan REAL WELL. The oil pan is thin, stamped steel - as such, it rusts out faster than anything else. If that is looking iffy, the engine will need to be pulled. On the plus side, it then makes the other things above much easier to do.

    FYI, the "distribution unit" you're referring to is called the thermostat housing. You do have a distribution unit, though, it's the water distribution manifold (quick drain)... the black plastic thing on the bottom front of the engine where water drains out.
     
  11. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    Thank Daze...
    Will take a look today a bit further...
    Fortunately drain pan was replaced 2 yrs ago...
    Yes wrong term on thermo housing and I did clean it best I could...

    Now I just need to find the plastic sleeve insert for thermostat somewhere today...
     
  12. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    The plastic sleeve is a pretty standard part. Being in Fla, there must be plenty of Merc shops around?

    Good luck, Dayz!
     
    Happy Dayz likes this.
  13. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    ...so i found a sleeve and reinstalled everything.. flushed best I could .. didnt pull the elbows.. no time and had to find the sleeve.. ran fine with muffs

    Taking her out tomorrow.. hopefully all is well for now.. planning a nice overnight

    Thanks for the help!

    [​IMG]

    [​IMG]
     
  14. Espos4

    Espos4 Active Member

    330
    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Nice engine compartment.

    Very clean and looks like plenty of room to work.

    I can't sit in mine, I have to lay on the cockpit floor and dangle my arms over the side into the engine bay to access anything on the front of the motor, that's after removing the front bulkhead. Not looking forward to next year's impeller replacement!
     
    Happy Dayz likes this.
  15. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    ...WELL DAMN...

    she still overheated this weekend...

    seems to hold 158ish at idle and plowing along at 1800rpm... would hold temp on plane for about 5 minutes and then start to tick upward... i would slow to idle and temps would drop..

    guess im pulling the elbows, risers and manifolds and doing a more complete cleanout and flush...

    ...and yes, fortunate to have room to work! another reason i wanted this model..
     
  16. CliffA

    CliffA Well-Known Member GOLD Sponsor

    Dec 29, 2009
    Lake Norman, NC
    2001 Sea Ray 340DA
    Name: 'Happy Place'
    4.5kW West. Generator
    Purchased Nov. 2014
    Fresh Water Use
    Twin Merc. 6.2L (MPI)
    Raw Water Cooled
    V-Drive Transmissions
    might want to check the water circulation pump on the engine....I had the very same symptoms on a 5.7L engine on a previous boat....I went through the ENTIRE cooling system and changed a lot of parts.....visual inspection of the circulation pump did not give any indication of an issue...no water weeping from the pump and the bearing for the impeller was tight....but it was the last component in the cooling system so I changed it for a new one....problem immediately went away....the only thing I can think of was the PO of the boat ran it in shallow in-land lakes in Florida...the bottoms of these lakes are sand...I am thinking that years of use in the shallow lakes caused sand to be sucked up by the water pump and circulated through the cooling system which may have worn down the blades of the impeller to the point the pump could not circulate enough cooling water at higher engine rpms....

    could also be a restriction in the water line that runs through the transom as mentioned before....

    good luck.....

    cliff
     
    Happy Dayz likes this.
  17. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Water in n water out, that simple. Seeing that manifold feed line was jammed tight it's probably a water out issue.
    I would disconnect those feed line 1 at a time and run the motor briefly on the flusher. The stream coming out the hose should look like garden hose pressure. If it's weak there back up. That pump body didn't look to hot either.
    What's that smartcraft water pressure gauge reading ?
     
  18. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley

    pressure reading is around 3.4 psi above 1000rpm....
     
  19. scoflaw

    scoflaw Well-Known Member SILVER Sponsor

    Aug 10, 2011
    cape cod mass
    1999 Powerquest legend 260 sx
    502 mpi Bravo 1
    Should be in the 15-17 range at WOT
     
  20. Happy Dayz

    Happy Dayz Active Member

    190
    Jun 26, 2017
    Sarasota, FL
    '06 260 Sundancer, 6.2, BIII, Kohler 5kw
    79' classic Kona Family Cruiser jet boat..
    6.2 w/ BIII, 502 w/ Berkekley
    well there is definitely a problem...somewhere
     

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