Yamaha 25 water pump issues

Discussion in 'Outboard Maintenance' started by rwillia5, Mar 14, 2014.

  1. rwillia5

    rwillia5 I Love microskiff.com!

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    I installed a new water pump kit on my Yamaha 25 2 stroke and got about 1 year out of it before it seemed to stop working properly. Got a new kit and installed it along with a new thermostat. It runs fine for several minutes before it stops pumping water. Removed thermostat and ran it hooked up to the hose and I get the same thing. Seems fine for several minutes and then no water flow. Doesn't appear to be a bad thermostat. The impeller that I just replaced really didn't look bad to me. Not sure what could be causing the issue. Any ideas?
     
  2. Creek Runner

    Creek Runner Well-Known Member

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    Replace the water pump housing, and also the water tube bushing.

    Pretty common with all motor manufactures.
     

  3. rwillia5

    rwillia5 I Love microskiff.com!

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    Thanks Creekrunner. Will do. I wondered about pump housing when I installed the kit. It looked like something that should have been replaced while I was in there but didn't have those parts at the time. Too eager to put boat in the water and go
     
  4. jmrodandgun

    jmrodandgun Well-Known Member

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    This is an invaluable piece of information. That stupid bushing almost cost me a motor and I rarely ever see it mentioned.

    part # 6L2-44366-00-00
     
  5. rwillia5

    rwillia5 I Love microskiff.com!

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    Hmm. I replaced 6L2-44368 and 44367 along with pump housing. Did not replace 44366 which would be at the top of the water tube. Think that's it? I'm getting no flow through the tell-tale now when I run it on the hose or in the water. No flow at all, just steam once it warms up. Think it could be blockage somewhere or do I need to replace that part? Rubber tube running to telltale isn't blocked, I've detached and blown through it. I'm running it with no thermostat while I work on it just to eliminate that variable.
     
  6. jmrodandgun

    jmrodandgun Well-Known Member

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    pull the lower unit and make sure the rubber grommet sealing the top of the pump to the tube is in good shape.

    This happened to me. When I took the lower unit off to repair the skeg the rubber grommet stayed on the tube, I had no idea it was missing. When I put the lower unit back on the pump would start sucking air and starve the power head of water. I took the lower off and shined a light up into the housing and saw the rubber seal stuck to tube. It has a little bump that fits in a hole in the top of the water pump to hold it in place.

    I would pull the lower unit and make sure the water pump is sealing property. Water pumps through the tell tale at all times, regardless if thermostat is open or closed
     
  7. jmrodandgun

    jmrodandgun Well-Known Member

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    http://youtu.be/lbWW8r_WYgc?t=3m12s

    Open this link. The video will start at 3 minutes and 12 seconds. This is where he discusses the rubber grommet on the water tube. No need to