2013 yamaha 4 stroke 70hp compression

Discussion in 'Outboard Maintenance' started by monte, Oct 28, 2013.

  1. monte

    monte I Love microskiff.com!

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    cold compression test done on a 2013 yamaha 4 stroke 70hp
    numbers are between 95- 105psi. does this seem right? around 150 hours. seems real low for such a new motor.
     
  2. DuckNut

    DuckNut Brandon, FL

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    I think compression should be checked on a warm engine. No idea what the compression should be.
     

  3. Brett

    Brett > PRO STAFF <

    Make sure intake flap is wide open when testing compression.
    With the butterfly closed it restricts airflow, giving lower readings.
     
  4. cutrunner

    cutrunner Cert. Yamaha technician

    Its fine
    Go find two other guages and see what they say.
    Guarante you they wil all be different. Possibly higher or lower
     
  5. cutrunner

    cutrunner Cert. Yamaha technician

    But I will buy it off of you for a discounted sum ;D
     
  6. Creek Runner

    Creek Runner Well-Known Member

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    Yamaha no longer recommends compression test on 4-stroke engines, A leak down test should be performed.
     
  7. cutrunner

    cutrunner Cert. Yamaha technician

    Agreed. Its a little more work but if you know what your doing it can tell you ANYTHING you need to know
     
  8. cutrunner

    cutrunner Cert. Yamaha technician

    Creek
    I'm up here at yamaha right now.
    Need any parts? ;)
     
  9. monte

    monte I Love microskiff.com!

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    its for a boat that im looking at picking up. boats not in my area and the owner took it to a dealer to for a check up. every thing else seems good. i may run my own when i see the boat in person.
     
  10. Creek Runner

    Creek Runner Well-Known Member

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    All I need is a hole in my head for working on boats! :D