4hp outboard

Discussion in 'Multihulls' started by guzzis3, Apr 25, 2021.

  1. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    The johnson 4hp long leg twin weighs about 12 kgs a little long in the tooth and getting harder to find but simple and long lasting. it would be feasible to set mounting brackets each side and run 2 motors if the current and headwind were really going hard. There's peace of mind in having a spare.You can get a little charge running a gadget off the flywheel. Just a thought.
     
  2. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    Thank you for the suggestion.
     
  3. guzzis3
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    guzzis3 Senior Member

    Is this the same as the evinrude ? There is a 4hp long evinrude for sale. I'm trying to organise getting across town to buy it.1990 model. It's cheap enough and I can do some experiments with it. Also wondering if it can be "hotted up" to 6hp. No idea where to look for this information.
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    The only difference is the color and the name.
     
  5. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    If I may.

    If you have eye troubles, running the boat will be more difficult in all aspects. That includes sailing and docking and mooring.

    The trimaran will be much harder to manage at the dock. The catamaran will be easier, but the engine setup ought to get good thought. The transistion should be quick from sail to power. This might even mean a key and a starter.

    If the catamaran has lots of climbing and such; that may be hard as well.

    I would consider, above all else, which boat is the easiest to operate in difficult conditions.

    A monohull with a bow thruster would probably be the easiest for you, followed by a well setup cat, and lastly the trimaran. Now, I am no trimaran experienced fellow, but I know enough about boats to tell you a big wide boat with 3 floating sections is no simple gal to steer at low speed.
     
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  6. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    A long leg is important, check closely for any exhaust escaping or cracks below the power head at the top of the leg, there's not much cast there if treated roughly.
    The 6hp is a bigger beast but pushing more fuel through the 4hp twin may be possible but spending money and studying that doesn't seem worth it..well to me.. The 3.3 is the lightest with no gearbox, you just spin it, so simple and versatile for thrusting sideways etc. I haven't found a long leg version though. China probably makes something,.. air cooled and very unlikely to get stolen.
     
  7. fallguy
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    fallguy Senior Member

    An important, overlooked detail in small outboards is the prop size, ttlf spurred my memory.

    You are going to want an engine that can allow a larger than smaller diameter prop. I have a 2.5 Yamaha reserve motor on my 16' skiff. I call it a reservc motor because it doesn't work well for trolling unless close to wot whch is too fast here. The prop is too small to go to the wind and the boat gets pushed around. A larger prop would help the situation, but there is no space(clearance to cav plate) for it, nor do I think it is recommended or any made last I checked.

    Too small a prop has too little torque and can't stay on course with a slight crosswind or headwind. She does fine wind at our back.
     
  8. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    You don't want to push those CR3 blocks past 4 hp. That was the high end of the range. They will take a lot of parts off the 6s though, fuel pumps and props are interchangeable. I ran a 6hp prop on mine for 20 years till I flipped the boat in saltwater and killed the top bearings. IMO, they were the best little outboards ever made. Not cheap at the time. I think I paid $750 for a 2.5 in the early 80s. Most expensive motor I have ever bought.:)
     
  9. guzzis3
    Joined: Nov 2009
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    guzzis3 Senior Member

    Thank you for the comments.

    I can see to the left in both eyes I've just got a massive blind spot to the right.

    As with many things I have strong opinions on how to organise a boat. Trailerable trimarans over say 25' throw up all sorts of problems before you try and dock the boat. I'm looking at either a moored cat or maybe a demountable one to 10m. The latter would be launched in autumn and recovered in spring for storage out of the water and maintenance. I've long been keen on teh cuddy/sportsdeck/nacel cabin cats. Obviously the different arrangments all have their pros and cons but the privacy and access/visibility forward are big pluses to my mind.

    I've found the model codes and got the model number off the seller. It seems to be a 1990 and long shaft. There were 2 prop options. The larger diameter shallower pitch seems to be harder to find. I assume this is the high thrust. Parts are patchy but I plan just to experiment with it so if I can organise getting over there I'll grab it and see how I go.

    Again very grateful for the comments.
     
  10. guzzis3
    Joined: Nov 2009
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    Location: Brisbane

    guzzis3 Senior Member

    Hi,

    I only just noticed this. Could you explain what a CR3 block is ?

    The evinrude I bought has the long leg model number but is a short shaft. Quite annoying. Anyway I'll do some experiments with it when I can then move it on.

    Everything seems to take 10x longer now. It's quite frustrating.
     

  11. trip the light fandango
    Joined: Apr 2018
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    Location: Rhyll Phillip Island Victoria Australia

    trip the light fandango Senior Member

    Having 2 has it's merits., I was also "shafted", the next one I bought from a nice bloke in Tassie was cheaper , better and included freight, but a short shaft.
     
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