Steering problem when extending the transom height.

Discussion in 'Outboards' started by valvebounce, Jun 4, 2017.

  1. valvebounce
    Joined: Dec 2010
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    Location: manchester uk

    valvebounce Senior Member

    My transom is 16",I have short shaft 1963 18hp Evinrude on it at present.
    I am looking to raise the transom 6" to take a 1999 25hp longshaft Johnson.
    It has what I think is Teleflex steering.
    The rod comes through the splashwell supported by a square ss plate which incorporates the universal ball joint.
    If I raise the transom,the rod will be rising at about 40% to the outboard.
    I can't see this working without some kind of adjustment bracket to keep the rod horizontal and parallel to the transom and connected to the outboard.
    I am tied to the fixed point of height where the plate enters through the splashwell.
    Is there a conversion kit available,or is there a bracket I can fabricate to suit.
    I prefer raising the transom for more protection from a following sea,or for launching.
    Any help will be gladly received. V
     
  2. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    I'm not sure what square support you're talking about, most just come through the opening in the splashwell with little to no support. And people just cut a new hole in the splashwell for the steering cable to come through if needed. Maybe a pic would help.
     
  3. valvebounce
    Joined: Dec 2010
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    Location: manchester uk

    valvebounce Senior Member

    I'll get a pic sorted out and post it O.
    The boat is only 14ft and I can't make a higher entry hole in the splashwell.
    The boat is fibreglass,with a nice planing hull,the draft is only 1ft.
    It has two seats,and a dashboard,the bow in front of the dash is covered.
    The deck is fibreglass.
    The stainless plate has 4 bolts and is bolted to the splashwell,it supports the universal joint for the steering rod.(Nylon ball)
     
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  4. Barry
    Joined: Mar 2002
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    Barry Senior Member

    [​IMG]

    On his older outboard, he does not have a through the engine mount tilt tube configuration so required an engine well mounted, gimballed system, it sounds like his is square, to provide a fixed support for the cable and then a ball joint on the motor for the end of the cable. Option 1
    On his 1999, he should have the through engine mount tilt tube opening with threads on the engine where you use a specific cable end that uses the large nut to attach it to. Option 3
    If his 99 was a tiller steering, he might have to change out a portion on the engine to accept the nut on the through engine mount design.

    He will likely have to change out the cable with the nut on the engine side as well. More than likely, but not guaranteed, the steering wheel end will not have to be changed as it is likely a rack and pinion in that era
     
  5. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    That's exactly what the situation is Barry,thanks for the info.The outboard had steering and no tiller on it,similar to your first diagram,and the splashwell support
    is the same but mine is square.The steering pick up point on my outboard is a flat bar with a large central drilling,with two smaller drillings either side.
    Do you think I will need to release the cable from it's fixed splashwell point so when I raise the transom it isn't working at a 40% angle?
    What I had in mind was a dropdown bracket from the outboard to the steering rod connection.I made up a similar bracket on the 18hp Evinrude.
    Maybe another option would be to use a bracket off the new transom as shown in diagram 2,there is enough spare steering cable to pull it through the splashwell.
    The boat is in good condition,although a bit dated,there are still pulley rollers from the original steering under the gunnels.
    The guy I bought the boat off had a 15hp Yamaha on it,but he stripped the connections out before I bought it.
    I fitted new control levers to suit the Evinrude.
     
  6. Barry
    Joined: Mar 2002
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    Barry Senior Member

    If you have the through the engine mount tube. If your current cable has the nut on the engine side, and you have enough length in the cable, you could just remove the well gimbal and hook it up.
    If it does not have the nut, then you only have to buy a new longer cable if you can match the steering wheel end to a standard cable. You would then remove your square boat well bracket. This will allow you to raise the cable a bit and dependingon the geometry of the well, there should be room to the cable to bend to take care of the change of height.

    You do not want to have the cable being attached to the ball on the engine at 40 degrees for a few reasons
    1) due to a 40 degree angle that you are thinking that you will have, the feed back to the steering will be about 33 percent more. Ie if you need to create a horizontal turning force in the cable of say 40 pounds, at 40 degrees, you would need to provide 52 pounds of force into the cable to turn the motor. I am guessing at the 40 pounds of horizontal force to turn the motor. Might be less and might be more. More feed back at the steering wheel
    2) if the cable is angled at 40 degrees, you will almost certainly create a situation where the entire cable from the ball to the mount will have some movement and the engine/boat will wander/cycle at higher speed. You don't want this.
    3) you will lose approximate 33 percent of actual motor travel side to side, ie effective horizontal stroke length loss due to the 40 degree angle

    You could, but I would not, build a bracket on the motor to lower the ball. You would need to ensure that you could tilt the engine with this bracket on. My concern would be that you will create a moment arm between the ball and the engine, so if it is not a 100 percent rigid design, you may introduce a higher wear or breakage situation. We had a 90 Evinrude in a 16 foot gullwing boat when I was 18 and the ball broke, in a split second the boat turned about 90 degrees, which produced some significant bruising and a bit of blood for the 4 occupants. Mind you it was a 90hp but loss of control at any speed is dangerous to the occupants.
     
  7. valvebounce
    Joined: Dec 2010
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    valvebounce Senior Member

    Your input is much appreciated Barry,thanks.The job sounds a bit tricky,although I could manage it.If the 18hp Evinrude was a bit later model I would stay with it.
    I got the 25hp at a very reasonable price,it's in very good condition with few hours on it.If I sold it I would make money on it.
    I'm thinking maybe sticking to a shortshaft might be the way to go.The transom would stand raising 2" to still take a shortshaft.
    I could fabricate a bracket from the outboard to the steering rod similar to the one I made for the Evinrude,which would keep the steering rod inline.
    A lot to think about,Haha.
    Thanks for your input once again.
     
  8. Barry
    Joined: Mar 2002
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    Barry Senior Member


    Ran across these pictures
    The lower picture is supposed to fit from 1991 and up Evinrude 3 cylinder and above engines
    This is for a twin dual rack steering control. Ie at the helm there are parallel rack and pinion attachments so for high performance engines you can have two cables dealing with the control of the engine. Redundancy and less movement/wander/cycle. This tilt tube would bolt to the front of the engine mount, ie where the ball is now on your engine. While it might be unlikely that you would find a direct part number application for the 25hp, perhaps if you started with a bolt on tilt tube, you could figure out how to mount the bracket which holds the tilt tube to your engine.
    The idea of having the rigid part of the steering rod within the tilt tube permits, or might permit you steer cable to come out of the current well hole and bend up to the engine

    If your new engine is a long shaft, you do not want to have it on a short transom as obviously the ventilation plate will be too low causing a lot of spray

    If your current cable has a nut to attach to the tilt tube and is long enough for the nut to attach to the tilt tube, this is a pretty cheap fix as long as you can bolt the bracket that holds the tilt tube to the front of the engine

    [​IMG]
    [​IMG]
     
  9. valvebounce
    Joined: Dec 2010
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    Location: manchester uk

    valvebounce Senior Member

    Now that looks like the answer,thanks.
    Just so we are reading from the same page,the ball is right next to the well wall,not on the engine.The rod comes through it and pivots at that point.
    With the tube and bracket in the top picture I will probably be able to incorporate an additional bracket.
    Like you said earlier,the range of tilt will need to be considered.
    Thanks for researching the picture,and thanks again.
     
  10. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    we need a photo
    does your new engine have a one piece exhaust housing or an adapter in it?
    Maybe its easier to make the 25 a 15" engine?
     

  11. valvebounce
    Joined: Dec 2010
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    Location: manchester uk

    valvebounce Senior Member

    Hi P,I've come to that conclusion,probably a lot less trouble to go with a shortshaft.
    It seems the original setup was already wrong,the transom was 2-3" lower than it should have been,even the shortshaft cavitation plate was 3" lower than the hull.
    The boat is a bit dated,but it has been well constructed and has a nice planing hull.I can't imagine what engine would have worked properly on it.
    The guy I bought it off said he had a 15hp yammy on it,and had used it in the Lochs in Scotland.
    After the info I got off Barry on previous posts,I have decided the only way to correct the steering is to release it from the fixed point in the splashwell and run the steering cable thro the hole and use a support bracket off the transom.This would mean I would need the setup as seen in pics on a previous post from Barry.
    I made a bracket for the 18hp Evinrude,but it restricts the tilt travel.
    I can afford to raise the transom 3" and still use a shortshaft motor.For the longshaft I would need to raise it 6-7".
    Shame to let the 25hp longshaft go,it's practically unmarked,and hasn't had much use.Not sure about the exhaust,but the model number is J25REEB.
     
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