Tutorial on water pump installation.

Discussion in 'Catfishing Library' started by Bubbakat, Oct 5, 2006.

  1. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Water pump change on a 25 H/P early nineties model.


    You remove the plate to gain access to the shift connector.

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    This is what you will see

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    you can the separate the shift shaft

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    After doing the above you can then remove the bolts that hold the lower unit on
    there should be two on each side and one under the trim tab. Remove the trim tab to access the hidden
    bolt.

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    You will find this bolted to the lower unit with the drive shaft running up through it.

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    Under the above cup you will find the impeller.

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    Under all that is the wear plate and the lower unit water intake cavity. You need to clean all the surface and
    inside the intake real good. This one has been in salt water so you can see the damage it can cause if left alone.
    On this model and keep in mind not all models are alike this shaft can be removed from the gear box and reinserted

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    Alright we have it cleaned out so lets replace it shall we.
    Install the new plate and gasket under it and use some brush on sealer that will most likely be brown in color

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    Here is the new cup. notice the sealer to hold the gasket in place and to seal it.

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    On these models, I think from the early eighties they Incorporated a metal like ring with a flat metal cap.
    If you will look in the outer cup you will see where the round metal plate fits into the cup. The plate has a small tab that sets inside a slot in the cup. The metal ring is then squeezed together
    not real hard now and inserted into the cup.
    It has two notches that go in first and lined up with the notches in the round plate

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    Grease the impeller up and insert it into the cup and metal ring while twisting clockwise.
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    If you will notice the white thing in the picture this is what holds the impeller in place while it is on the drive shaft.
    You can take a little sealer to help hold it in place while you slide the impeller down on it.

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    Bolt your housing back down and install your new grommet

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    Add a little grease to the splines on the upper end of the shaft and the new O ring and reinstall your
    lower unit. Don't put grease on top of the drive shaft it can cause the shaft to preload the crank and do internal damage to
    the engine.

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    Reinstall your bolts and hook up your shift shaft and you should be ready to rock and roll

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    Now Guys and gals use common sense when doing this. Don't force nothing and use a digital camera if you have one.

    I hope I didn't miss anything in this.:embarassed:
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Your shift shaft will disconnect totally different. There's a hair pin like thingy you'll pull loose from the shift mechanism. It'll be low and to the rear of the right side bottom carb. Once you get it out, push the rod it goes through to release the pin that goes through the shift shaft

    If you disconnect the shift control cable, it'll make life easier. Once the shift is disconnected, remove the bolts, don't forget the one under the trim tab, and lower your lower unit.
     

  3. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Just thought I'd mention the adhesive I use for those waterpump housing thin rubber gaskets.

    It's widshield gasket adhesive, and that's the first thing I do when I open a new water pump kit, install the gasket so it'll be ready when I put it over the impellor.
     
  4. capnmorgan

    capnmorgan New Member

    Messages:
    40
    State:
    Texas
    I work on Mercurys and the only difference is you don't have to disconnect any shift linkages.Just make sure you linethe shifter back up or you'll have no gears.

    And FYI if you have no grease, WD-40 works great. Not as messy
     
  5. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Those half moon style keys are called Woodruff keys. For those other style keys, I just talk dirty to it and they stay in place after a few try's:lol:
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill


    Billy the only thing different would be the shift connector. It should be located in the area where the lower unit splits. You take all the bolts out and put the motor in reverse and it will drop down about 1 to 1 1/2 inches and expose the shift connector. It will be a flat brass collar with two bolts one on each end. You only need to take out one of them and I use a 1/4 drive extension to get to it. It is a little tricky to get back in but it has been done several times.