Check valve screen

Discussion in 'Outboard Maintenance' started by Dadvocate, Aug 11, 2011.

  1. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

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    How important is the check valve screen and what is the check valve function on the leaf plate of 1984 johnson 15.
     
  2. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

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    There is a picture here http://www.sschapterpsa.com/ramblings/OB%20images/reed_valves.jpg
     

  3. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

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    Scared to start this motor new rings, seals, thermostat, etc. installed don't want to mess anything up during break-in.
     
  4. cutrunner

    cutrunner Cert. Yamaha technician

    Buy a good aftermarket reed setup, they say they help top end, but they definately smooth idle
     
  5. Brett

    Brett > PRO STAFF <

    Going from memory, 20 plus years ago, I think that screen
    and check valve are part of the oil scavenging system.
    Pulls excess 2 stroke oil out of the bottom of the crankcase and back into use.
     
  6. Dadvocate

    Dadvocate If it ain't broke tweak it a little....

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    Talked to a mechanic he thinks by design it is to keep fuel from pooling. He did not think it would harm motor to run without screen. Thanks for your reply.
     
  7. DuckNut

    DuckNut Brandon, FL

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    I don't know the technical terms are but Brett is on track. What they do is to create a little bit of pressure and surface tension so the mix is delivered in a controlled manner and not spit through the hole.

    Similar to the reason your house faucet have screens in them.