Issue getting on a plane with 280DA 2003 twin 4.3MPI and reach max cruising speed

Discussion in 'The rest of the world' started by Jmamacan, Apr 21, 2013.

  1. Jmamacan

    Jmamacan New Member

    2
    Apr 21, 2013
    Sydney
    2003 searay sundancer 280da
    Twin mercruisers 4.3mpi stern drive
    Hi there , i have had major issues over the years and had the boat serviced by several mechanics only to find that the best one down here in the sutherland shire cronulla in nsw australia can opnly get the boat to 14.5knots at 4200rpm.

    It astounds me to find that friends of mine have 20 year old 28 foot searays that does 24 knots comfortably. Well the boat has been antifouled legs serviced and engines tuned. The computer apparently reports the engines as running at optimal performance. So what is the issue no mechanic has yet been able to resolve this for me . Some tell me it may be the gear ratio in the legs others tell me that it could be the props. Where do i start, i am not mechanically minded so hence in the hands of the gods! the mechanics.

    I am told that this is the best I can get but I am not convinced. Where do i start? please help or put me in touch with someone that can help. We now only hang out local in the Port hacking river as i dont have the confidence in the boat to go outside. It travels comfortably at 8 knots but as soon as you give it some throttle it cavitates heaps of water in the stern near swim platform and all it does is chews up fuel. Drop down to 2000 rpm and runs beautifuly but only at 8 knots. Why please help!
     
  2. KC_Sundancer

    KC_Sundancer New Member

    Sep 8, 2009
    Munising, Michigan (Lake Superior) Pictured Rocks
    1985 270DA Sundancer,Simrad 4G Radar,Lowrance Gen2 GPS/Sonar/Structure Scan,F350 7.3l Diesel, tri-ax
    twin Mercruiser 185R's (v6's) w/SE106 drives, "High Five" stainless props, Mercury 280 RIB w/9.9 Mer
  3. Ruff Life

    Ruff Life Member

    105
    Sep 20, 2011
    Wisconsin
    1991 350/370 Sundancer
    Twin 7.4
    My 2000 270 with the twin 4.3 will top out at 38 knots/44 mph at about 4400 rpm. I cruise at 32 mph at 3200 rpm. Usually have two adult full fuel, water and loaded for weekend trips. Your 280 should only be a couple knots slower. I have no issues getting on plane. Something is definitely wrong. I normally have tabs up and full trim down to get on plane and then trim up. If you are actually getting that rpm and those speeds you have extreme prop slippage. Do you trim full down to get on plane? Even trimmed full down and full throttle you should see 28-30 knots easy.
     
    Last edited: Apr 21, 2013
  4. Jmamacan

    Jmamacan New Member

    2
    Apr 21, 2013
    Sydney
    2003 searay sundancer 280da
    Twin mercruisers 4.3mpi stern drive
    I appreciate your inputs, and have organised to slip the boat for antifoul an will get the props removed to check pitch and diameter, but again i appreciate the assistance and prop spillage sounds like the issue, if i may ask what props do you have on your 270 as a matter of interest.
     
  5. Ruff Life

    Ruff Life Member

    105
    Sep 20, 2011
    Wisconsin
    1991 350/370 Sundancer
    Twin 7.4
    19 pitch and drives have 1.62 gear ratio
     
  6. Bucit

    Bucit New Member

    Mar 12, 2010
    St. Petersburg Florida
    2005 280 Sundancer
    2004 SPD-104 Achilles w/ 8hp Yamaha
    Twin 4.3 MPI's with Alpha drives.
    I have the same set up and reach 4900rmps with top speed over 49mph (very light fuel, water and gear). Fully loaded I run around 46mph. My boat does not have bottom paint though.
     
  7. Gunn

    Gunn Active Member TECHNICAL Contributor

    Oct 4, 2006
    Potomac River - MD
    2003 280DA and 1995 Sea Ray 175
    Twin 4.3l and 3.0l, all w/ AlphaI GenII drives
    Are you drives moving to the full down position correctly? Check to make sure your trim cylinders on the outdrive are more or less fully compressed. What you are experiencing is something that would happen if the drives were up in any location (like cruise configuration). I'd forgotten to trim down once or twice and that will exhibit your symptoms.

    Otherwise, like others have said this boat will move along nicely on plane. I often see 28-30kts @ 3600rpm cruise speed.
     
  8. Offshore57

    Offshore57 New Member

    49
    Nov 10, 2014
    Hampshire UK
    270 DA 1992 - Voodoo Doll
    2 x V6 Mercruiser
    You could have a prop spinning issue where they are ok without too much load, say, at 8 knots, but as soon as you ask for more the rubber bush in the centre of the prop spins....and loads of exhaust gas in the water but no go............check and see if they have rubber centres around the splined piece...if they dont, it could be a nylon adapter....
     

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