Holy Crap ! My Compression Gage Is Possessed !!!

Discussion in 'Outboard Maintenance' started by noeettica, Jun 20, 2014.

  1. noeettica

    noeettica Well-Known Member

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    Holy Crap ! My Compression Gage Is Possessed !!!

    Bought a motor from a "Certified Master Marine Mechanic" that advertised 150 PSI

    Got it home and am getting 100 !!! :mad:


    I am going to check my Gage against another known Gage ...

    If he Can't do some explaining OFF WITH HIS HEAD !!!


    [smiley=greenchainsaw.gif] [smiley=frustrate2.gif]
     
  2. cutrunner

    cutrunner Cert. Yamaha technician

    Every guage reads different,.
    I even proved it to the snap on guy. Took two of the same brand new guages off the truck and they were 13 psi off on the same engine
     

  3. noeettica

    noeettica Well-Known Member

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    I knew a guy he had two ...One for Buying and one for selling ...

    I can see 13 not 50

    But the seller may have checked hot ... I checked cold ...
     
  4. cutrunner

    cutrunner Cert. Yamaha technician

    That will do it
    as long ss they are even and realistic, not to low
     
  5. noeettica

    noeettica Well-Known Member

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    Thank You :)

    another weird factor is the bolts for the lower have not been out for a long time ...

    That to me equals NOT Equal fully "Checked Out" :mad:

     
  6. swampfox

    swampfox 01 Hells Bay Guide.07 ECC LOSTMEN-sold

    Exactly how are you checking compression? gives us the exact process step by step. Because it can make a huge difference in numbers. From one method to another. I think I may know why you are getting a lower number. But want to hear it from you. Not that what you are doing is wrong. You just have to compare apples to apples. ;)
     
  7. noeettica

    noeettica Well-Known Member

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    Lock carb open... Spray in fogging oil pull engine through to disperse ...


    pull plugs ,,,shoot in more fogging oil and pull through several times

    Install gage do test 8 pulls
     
  8. swampfox

    swampfox 01 Hells Bay Guide.07 ECC LOSTMEN-sold

    Ok that's how I was taught. Just wanted to make sure all plugs were out. Some will just hit one ata a time. Which can lead to lower numbers. If they don't do a good job of bumping it over. You should be getting a high consistent number with plugs out. There is less resistance. So you can reach a higher RPM in theory possibly getting more compression.
     
  9. noeettica

    noeettica Well-Known Member

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    I have one motor reading too high !

    Guess I'll have to go run the Snot out of it to see if it comes down a bit ... LOL :eek:

    Break out the KLOTZ !!!