Sundancer 300. Won’t get on plane.

Discussion in 'Sport Cruisers' started by Ryan Dykhouse, Jul 13, 2019.

  1. Ryan Dykhouse

    Ryan Dykhouse New Member

    4
    Jul 13, 2019
    2004 Sundancer 300
    (2) Merc 5.0’s
    2004 Sundancer 300 with twin 5.0’s. I know this the the standard engine setup and the boat certainly isn’t overpowered. But, if I have full fuel and 6 adults on board, I can’t get the boat on plane. Literally drove for 2 miles last night before the right wave combination set me up to gain some speed to get the boat on plane. Any thoughts??? New outdrives and new bottom paint.
     
  2. JVM225

    JVM225 Well-Known Member GOLD Sponsor

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    Is this a new condition?
    Has anything, other than your new drives, changed with the mechanicals on the boat?
    Can you reach rated RPM’s at WOT?
    You may want to consider talking to a good prop guy.
     
    Ryan Dykhouse likes this.
  3. hottoddie

    hottoddie Well-Known Member

    Jan 11, 2012
    Boston/Cape Cod
    1986 Sea Ray 390 EC
    Garmin 4212 Chartplotter
    Garmin 24 HD Radar
    Garmin 546s Plotter
    454 Crusaders
    Fresh or salt water? Has the boat sat for an extended period of time since being used? Vibrations?
     
  4. dtfeld

    dtfeld Water Contrails GOLD Sponsor

    Jun 5, 2016
    Milton, GA
    410 Sundancer
    2001
    Axiom 12 MFD
    Cat 3126 V-Drives
    Were the outdrives the same ratio and props?? Is the drive trimmed all the way in?

    I had a boat that wouldn't get on plane and I had to use full down tabs and send a couple people forward to get her up on plane.

    The solution was to trade the boat in on a larger boat with the largest engines the factory installed. Since then, I've always looked for the most powerful engine offered from the factory when upgrading.
     
    Ryan Dykhouse and scoflaw like this.
  5. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    I had the same boat, same year with the 5.7 350Mag and BIII. If all six adults were in the back of the cockpit I had to use the tabs to get on plane with full fuel. I think it's just the nature of the boat, but maybe Ididntdoit or another 300DA owner will add their experiences.
     
  6. Ididntdoit

    Ididntdoit Well-Known Member GOLD Sponsor

    Dec 5, 2007
    New England & South Florida
    Boatless
    Boatless
    yes - something is definately wrong - i have run my boat heavily loaded and never had a problem....do you have BIII drives? should be 2.20 with 20p props.....once you were on plane, were you able to hit at least 4600 rpm on both sides? does one motor lag/require more throttle than the other?
     
  7. Ryan Dykhouse

    Ryan Dykhouse New Member

    4
    Jul 13, 2019
    2004 Sundancer 300
    (2) Merc 5.0’s
    All good feedback.

    Props are p22 but yes BIII drives. Both engines run similar and I can get the rpms once on plane. When the boat starts coming over the top to plane though, the rpms do come up a bit and it sounds like some cavitation possibly.

    There is a highly regarded prop shop near me. Definitely going to seek their advice.
     
  8. Ryan Dykhouse

    Ryan Dykhouse New Member

    4
    Jul 13, 2019
    2004 Sundancer 300
    (2) Merc 5.0’s
    Fresh water. No boat has been used quite consistently.
     
  9. Ryan Dykhouse

    Ryan Dykhouse New Member

    4
    Jul 13, 2019
    2004 Sundancer 300
    (2) Merc 5.0’s
    Has been this way since I’ve owned the boat....both before and after outdrives. I can reach the RPM once I break plane but I’m fore sure going to consult with my local prop shop.
     
  10. Gofirstclass

    Gofirstclass Well-Known Member GOLD Sponsor

    Apr 20, 2010
    Tri Cities, WA
    1995 550 Sedan Bridge,
    2010 Boston Whaler 130 Super Sport,
    1981 Boston Whaler 130 Sport,
    CAT 3406C's, 580hp.
    Ryan, I'm guessing when you're trying to get on plane with that number of people and full fuel and water there's just too much weight aft.

    I had a 330 with 5.7L's and had no trouble getting it on plane but had to use quite a bit of trim tab if I was running with full fuel and water and several passengers.

    Also, how clean is the bottom on the boat? It doesn't take much gunk on the bottom to make getting on plane difficult.
     
  11. JVM225

    JVM225 Well-Known Member GOLD Sponsor

    Apr 8, 2008
    Farmingdale, NY
    2002 410 Sundancer, Monaco Edition.
    3126 Cats.
    Google PropMD. That’s who I called back when I had my 300 Sundancer. Their recommendations were on the money and they had great prices at the time.
     
  12. Ididntdoit

    Ididntdoit Well-Known Member GOLD Sponsor

    Dec 5, 2007
    New England & South Florida
    Boatless
    Boatless
    22p props are a problem......my load last week was 4 people (3 on the aft bench) a 200 lbs dinghy on the swim platform, full fuel, full water and enough bottled water and food for 4 people for a week, and the boat has a gennie too.....also, thats with no tabs
     
  13. Bridog

    Bridog Well-Known Member GOLD Sponsor

    Oct 4, 2006
    Gulf Shores AL / Brick NJ
    2016 19SPX OB
    Mercury 150 4S OB
    IMG_3179.PNG
    That's interesting. According to the parts list from 2004 the 22" cup is correct. Did you change yours out?
     
  14. Ididntdoit

    Ididntdoit Well-Known Member GOLD Sponsor

    Dec 5, 2007
    New England & South Florida
    Boatless
    Boatless
    no - if i had 22's i wouldnt meet max rpm with 5.0s.....maybe the drive ratio is different
     
  15. Ididntdoit

    Ididntdoit Well-Known Member GOLD Sponsor

    Dec 5, 2007
    New England & South Florida
    Boatless
    Boatless
    just looked at the prop and drive matrix for 2004 and 2005 - all use a 2.20 drive - in '05 it uses 22p cupped props with no bottom paint and 20p (non cupped) with bottom paint (which mine had from the factory) in '04 it lists 22p cupped props with no bottom paint and 22p (non cupped) for boats with - same exact boat and motors.....

    FWIW - If I was getting new props, i would go 19 or even 18p
     
    Last edited: Jul 14, 2019
  16. Brite Idea

    Brite Idea Member

    156
    Nov 5, 2011
    Long Island, New York
    270 Sundancer 2000
    twin 4.3 TBI Merecrusier Alpha Gen II counter rotating drives
    For what it's worth I bought a boat in 1999 and it came with a 5.7 with a Bravo III propped with a set of 24 inch pitch. I felt from day one it was over propped but the dealer argued with me that the manufacturer set it up like that so it must be right. I could only get to the bottom of the WOT range. I ended up calling the boat manufacturer direct and they said that's the correct prop, I ended up calling Mercruiser who after I gave them all the details called the dealer and setup a prop swap. We switched to 22 inch but I have no idea about cupped or not anyway I picked up about five hundred rpm and the boat instantly performed much better. I think your boat is over propped.
     

Share This Page

Show Sidebar