Results 1 to 7 of 7

Thread: Merc 3 liter with NO GO!

  1. #1
    Steph Adams
    I have a 2000 LaveyCraft Sebring 20'8" with a Merc 3 liter, trim and jack plate. This thing won't pull a tube let alone a skier. I have tried everything from a 21-3 to a 24-4 blade and all I get is cavitation or bogging. I have tried various port sizes on the bravo line as well. Merc says the motor is putting out power but the only way to plane is to put everyone in the front of the boat and go slow.
    I could have done this with an electric motor..any thoughts before I hand this motor back to Mercury.

  2. #2
    Bjorkswede
    Have you tried using a bolt-on cav. plate fin like the Dolphin, etc? I use the Sport-Trac SE and am very pleased with it's performance. Just my 2 cents...

  3. #3
    Bowman
    Originally posted by Steph Adams:
    I have a 2000 LaveyCraft Sebring 20'8" with a Merc 3 liter, trim and jack plate. This thing won't pull a tube let alone a skier. I have tried everything from a 21-3 to a 24-4 blade and all I get is cavitation or bogging. I have tried various port sizes on the bravo line as well. Merc says the motor is putting out power but the only way to plane is to put everyone in the front of the boat and go slow.
    I could have done this with an electric motor..any thoughts before I hand this motor back to Mercury.
    This is virtually exactly what happened to me.
    I would start to rise then the boat would go down at the back and lose power then slowly bite and move off.
    After trying approximately 8 props I found that a big hub 26" trophy really worked for all situations.
    I think the actual problem is blow by from the exhaust over the blades.
    The small hub is ok for some boats but leaves a gap for the exhaust to escape and run over the blades. Using the big hub seems to stop this. Strangely the 26 pitch had more pull (on my boat) than the lower pitches.
    [This message has been edited by Bowman (edited June 14, 2001).]
    [This message has been edited by Bowman (edited June 14, 2001).]

  4. #4
    anthony
    steph.those 20.8 are heavy and they like alot of set back.whatkind of jack plate are you using,if at all,how much set back.for skiing you can't beat the hi-five,for flatout try a mazco re-4.a 26 should be a good start.

  5. #5
    mrjetskey1
    Hi Steph
    My wifes ski boat is 18.5 searay skiray it is heavy as it is a true searay.she use a 2.4 merc stock with a merc hi five 19 pitch prop with excelent results.of course it will only run 58 mph without overeving but pulls like a 20 mule team just a idea
    take care marv in texas

  6. #6
    dragally
    Got a fiend with the same problem. He now uses a 26 bravo. Runs in the 90's. He has 1.62 gears and this seems to be the only prop the motor likes.
    DA

  7. #7
    HavasuBarney
    I have a 1998 300.
    Here's the deal on these big dogs,
    Your gonna need a large hub prop, I too think it is exhaust related.
    The other thing need is trim, the 300's are not set up with neg trim from the factory. You will need to put it in your setback, I added 20 degrees.
    The large hub Bravos, Mercruiser and Mercury, get the Mercury with "swirled" vents. I have 1.125" holes drilled in mine.
    Then it is about finding that sweet spot, it is there! Mine has to do with my trim angle, at the right angle, no matter what height my jackplate is at, I leap out of the hole and pull strong to 80, climbing to 88 on GPS with a 26p.
    When you find the right negative trim angle, your prop will "break loose" not spin, and catch about 3000 - 3500 rpm and jump out of the hole.
    I'm in Havasu, always around, email me if your gonna be in Havasu and we'll love that 300 again!

Similar Threads

  1. GM 8.1 Liter Intake
    By desertbird in forum Sandbar
    Replies: 5
    Last Post: 04-03-2007, 11:52 AM
  2. 6.2 liter diesel
    By slowinhavasu in forum Sandbar
    Replies: 16
    Last Post: 09-07-2006, 01:51 PM
  3. 6.0 Liter Oil Leak??
    By laveydayz in forum Sandbar
    Replies: 3
    Last Post: 06-27-2006, 09:35 PM
  4. 4.6 Liter Expedition.
    By dmontzsta in forum Sandbar
    Replies: 10
    Last Post: 04-10-2005, 09:21 PM
  5. 6.0 liter psd
    By Havasubum in forum Sandbar
    Replies: 7
    Last Post: 06-09-2003, 08:13 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •