yamaha tell tale

doolittle3701doolittle3701 Posts: 162 Deckhand
When running my 2007 yamaha 150 4 stroke in a tank of water, the tell tale (water pump ) indicator does not produce any flow. The water pump impeller was recently replaced and two months ago the tell tale was shooting out water in a steady stream. What are the possible causes for this behavior? The thermostat on the engine has never been replaced.


  • snookaffinitysnookaffinity Naples, FLPosts: 1,117 Officer
    Have you attempted to clean out the tell tale tube with fine wire or fishing line? Could be salt build up in the tube.
    "It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt." - Mark Twain
  • shamrock1188shamrock1188 Posts: 272 Deckhand
    Mud dauber making a nest in your tell tale tube. Two months is to long to let a boat sit get out and use your boat more. 
  • gmiller0737gmiller0737 Posts: 649 Officer
    I agree with those above Try cleaning the Outlet with a piece of stiff wire if it's  clean follow the hose that connects to the tell tale to where it connects to the Powerhead remove hose & clean the fitting @ Powerhead I have had a piece of Debris in mine before

  • doolittle3701doolittle3701 Posts: 162 Deckhand
    Thank all of you for your comments. I know that the tell tale hose is clear. Gmiller0737, I have taken that hose off the power head a nun run water through the powerheaqd, and out through the flushing fitting under the cowling, and everything seems open. I also ran water in through the flushing connection and water ran through the powerhead and out the tell tale. The mechanic who recently changed the water pump impeller suggested the problem might be with the thermostat. He suggested changing the thermostat since it has never been changed. When you remove the thermostat and have the cover off you can start the engine while it is supplied with water, and water should come out of the thermostat fitting if the water pump is pumping. In any case he suggested that the thermostat should be checked/replaced every time the water pump impeller is changed. 
  • shamrock1188shamrock1188 Posts: 272 Deckhand
    If your thermostat is open or closed you still will have water squirting out your tell tale. Is your motor over heating? Is your pick up clogged? Have you ran your motor with out water? Your new impeller will burn up quickly with out water. 
  • Grouper GeniusGrouper Genius Posts: 1,384 Officer
    Have you ever done this before? Have you had the "tell tale" flowing before in a tub?

    I say this because I used to with my F250. You have to get the water level above the foot completely. Not just the lower intake. 

    2400 CC Sea Chaser-Yamaha F250-Bad **** Tower (SOLD)
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  • m9000m9000 Posts: 2,044 Captain
    How far  into the water is the lower unit? I believe outboard  water pumps need to be fully submerged in a tank of water to pump.   Try submerging the lower unit at least 6 inches below the level of the water pump.   If  water is flowing out of the telltale when attached to the hose flushing device, you don't have an obstruction in that portion of the water passages.  Thermostats are way above the circuit that feeds the telltale hose and I don't see how an open or closed or broken thermostat would affect the telltale  waterflow.  Do you get  water flow out of the telltale  if you use a rabbit ear flushing device?
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