Yamaha Overheating - Could Use Some Help

Discussion in 'Boats, Blinds, & Gadgets Forum' started by smashdn, Dec 4, 2020.

  1. Bullet21XD

    Bullet21XD Elite Refuge Member

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    So I wonder...

    Is there another cooling system available for that(or near) year production?

    I had a Mercury Promax a while ago. For that particular model over several years, there was 2 different cooling systems. Different pump housing, different tube, different gaskets. My motor came with mix matched parts. Some for one system, some for the other. After the second time it burned up pistons, I researched it further and found a guy that explained this to me on Fastbass. After all the proper parts were installed, no more issues.

    Just a thought.

    All the part #'s were correct for the motor, on paper. They just didn't work together.
     
  2. smashdn

    smashdn Elite Refuge Member

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    20210615_181133.jpg

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    I am going cinch a zip tie around the gasket on the water tube to keep it from pushing up the water tube away from the pump housing.

    Plus run something up the water tube.
     
  3. smashdn

    smashdn Elite Refuge Member

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    Water tube clear all the way till exhaust jacket.
    Ran on muffs with water low intentionally to ensure I was overpressuring the impeller and getting false pressure. I had a good stream from tell-tale the whole time. Checked places with temp gun. Nothing on heads was ever over 129. Hottest spot was middle of exhaust plate at 143. No alarm.

    Took opportunity to run a can of sea foam through it. Ran until whole can was sucked up. Shut it down and let it soak while I put new line on a rod and tied a couple of jig heads on my bait rod.

    Fired back up and let it smoke. Revved it a few times to blow it out and let it run for about 15minutes again.

    No alarm.
     
  4. smashdn

    smashdn Elite Refuge Member

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  5. metalworx

    metalworx Senior Refuge Member

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    Me thinks this has been your problem all along, losing water around water tube where it goes in water pump because seal was off water pump and shoved up the pickup tube
     
  6. smashdn

    smashdn Elite Refuge Member

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    That being the case the design sucks. Nothing in any of the diagrams (or having the parts in hand) leads me to believe I installed something incorrectly. Would you agree that the water pressure from the tell-tale seems adequate? Especially given that apparently Yamahas are known for having (but running fine) on lowish water pressure.
     

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