115 Four Stroke Yamaha Speedometer

Discussion in 'Bubba's Outboards' started by Bobpaul, Jan 5, 2006.

  1. Bobpaul

    Bobpaul New Member

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    3,039
    State:
    Supply NC
    Hi Jerry, The Speedometer works like all others except no external pitot tube pick up.

    It does come from a small hole in the leading edge of the lower unit. A thin plastic tube comes up from that and dies out under the power head. It'll be painted the same grey color as the engine, with a hose barb plug in it.

    If it's never been hooked up, the hose barb will need to be clipped at the end, to allow the water pressure through to the speedometer hose you hook up to it.

    The hose should be coming out with your wire harness and controls, through the lower cowling.

    Let me know if you find it.
     
  2. Bobpaul

    Bobpaul New Member

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    3,039
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    Supply NC
    As far as accuracy goes, boat speedometers usually favor the boat. A GPS is the way to go to be sure.
     

  3. metalman

    metalman Well-Known Member

    Messages:
    3,447
    State:
    IN
    Name:
    Winston
    Jerry,
    I have a F115 Yamaha with the same arrangement as you. It seems that the little hole in the front of the lower unit is very prone to blockage. I have pretty much given up on trying to keep my speedo working. Don't be suprised if your speedo quits if you run in muddy/murky water...W
     
  4. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Because you have it, doesn't mean you have to use it.

    Get a standard speedometer pick up tube and route your tube from the speedometer to it and plug the hose coming out of your engine.

    The engine pick up is a very small hole that's hard to unplug. It could be more convenient to use the externall pick up for cleaning purposes if nothing else.
     
  5. Knoxcats

    Knoxcats New Member

    Messages:
    57
    State:
    Knoxville, TN
    My Honda BF50 has the same arrangement, and the hole is prone to blockage. Here's an easy way to clear the tube. Take a small drill bit that is just slightly smaller than the hole. USING YOUR FINGERS, turn the drill bit into the blockage and remove it.

    You can be sure by pulling the tube apart and blowing air thur it to be sure it's clear.