Fish and Chips

Discussion in 'Multihulls' started by guzzis3, Apr 8, 2017.

  1. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

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  2. jamez
    Joined: Feb 2007
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    Location: Auckland, New Zealand

    jamez Senior Member

  3. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    Not much clearance, but it does seem to be trimming low at the stern in the other pix.
     
  4. Manfred.pech
    Joined: Apr 2010
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    Location: EU

    Manfred.pech Senior Member

    That might be the problem. A 9,9 Yamaha weighs in the lightest version 93lb (42kg), the high thrust 104lb (47kg) without fuel. Two of them at the stern with fuel is a lot and a bad trim.
    http://www.boats.net/outboard_motor/Yamaha/9.9HP/parts.html

    http://www.teamscarab.com.au/7.3cat/design.html

    Length Overall................. 7.3m (24' 0")
    Beam Overall................... 4.6m (15' 0")
    Width on trailer............... 2.5 (8' 0")
    Draft.............................. 375 mm - 1250mm (1'3" - 4' 0") pivoting boards
    Displacement to DWL........1600kg (3520#)
    Weight.............................(approx) 950kg (2090#)
    Main Sail........................ 22 sq m (240 sq ft)
    Jib........................... 8 sq m (86 sq ft)
    Mast height...............9.65m (31' 8 ")
    Construction.............6mm plywood
     
  5. Ray Kendrick
    Joined: Jun 2007
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    Location: Australia

    Ray Kendrick Designer

    Hi,
    The photo certainly appears to suggest that the cat is overloaded and possibly not built to plan. The floor of the demountable cockpit as designed is just below (25mm) the bottom of the beam. The design specifies one 9 to 10 hp outboard mounted at the centre of the beam.
    Regards
    Ray Kendrick
     
  6. redreuben
    Joined: Jan 2009
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    Location: Beaconsfield Western Australia

    redreuben redreuben

    The design has been butchered, probably why its for sale, there shouldn't be anything below the rear beam let alone a huge boxy cockpit, maybe it was built by a mono sailor ?
    Still, nothing a chainsaw wouldn't fix :D
     
  7. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    I don't think an extra 9.9 O/B's weight is of any significance. Not a chance !
     
  8. jamez
    Joined: Feb 2007
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    Location: Auckland, New Zealand

    jamez Senior Member

    Think about it. 2x9.9's + 20 litres of fuel is probably 20-25% of the payload. Right on the back. Choice. Take them both off and i'd bet it floats level.
    A single 5-8hp LS 2 stroke would be ample for a boat that size and mounted further forward on a GBE style centre pod would be even better. It must be frustrating being a designer and seeing people f**k your boats up like that.
     
  9. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Any 23 foot boat that is unbalanced by a 9.9 hp outboard is a ***** ** *** to start with.
     
  10. jamez
    Joined: Feb 2007
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    Location: Auckland, New Zealand

    jamez Senior Member

    Get real dude: most small multis are weight and trim sensitive. Doesn't make them heaps of ****, even if the less discerning might struggle with the concept ...........
     
  11. basil
    Joined: Apr 2005
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    Location: aUSTRALIA

    basil Senior Member

    Fair suck of the sav Cobber - thats a bit harsh. I think Ray Kendrick designs fine boats and you should go and wash out your mouth with soap.
     
  12. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    Give me the figure for the difference in trim by adding 50 kg ( less than 3% of the hull weight) to the stern. In this case it is actually forward of the stern. If that is enough to bugger things up, then what can I say ! The rear view shows the hulls are not that slender.
     

  13. brian eiland
    Joined: Jun 2002
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    Location: St Augustine Fl, Thailand

    brian eiland Senior Member

    I installed a single (steerable) 9.9 Yamaha 4 stroke OB on the first Louisiane 37 footer I imported to the USA. It pushed that boat a 7 knots in flat water, and was very maneuverable in close quarters once you got use to it. (steerable engine/prop is key word/concept)

    No need for twin OB's on that 24' design.
     

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