Road King 80ci compression values

Discussion in 'Engine, Fuel and Exhaust' started by Sport40, Oct 16, 2011.

  1. Sport40

    Sport40 Member

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    Hello guys,

    Today I checked the cylinders compression values.
    I recorded about 140 psi on each cylinder.
    But the overhaul manuel (Clymer) says that the standard value is 90 psi.

    The engine had 120 000 kilometers no leak and no smoke.

    What do you think ?

    Thank you :worthy
     
  2. glider

    glider Veteran Member

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    90 lbs compression is time to rebuild. You're OK with 140 if it was done right.
     
  3. Sport40

    Sport40 Member

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    Thank you Glider.

    I understand, 90psi is the minimum record value before rebuildiing ?
     
  4. glider

    glider Veteran Member

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    Compression is what gives the engine the power. When you are low on compression the engine has no get up and go. Most times when you get below say 100 lbs, it's time for a rebuild but an accurate compression test should be done first with the throttle open and the slide in the carb lifted for best results.
     
  5. Sport40

    Sport40 Member

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    Of course.

    I followed this procedure: Harley Davidson Community

    :s

    So, I think now that 140 psi is a good pressure to ride still many miles :rider
     
  6. glider

    glider Veteran Member

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    I wouldn't give it another thought at 140 lbs. For a 98 bike, it's good.
     
  7. Sport40

    Sport40 Member

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    Thank you very much, I can ride quiet now.
     
  8. Jack Klarich

    Jack Klarich Expert Member

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    Equal pressure in the cylinders is always a good thing I say ride it some more miles and check the compression each time you pull the plugs:s
     
  9. nitroracer

    nitroracer Member

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    as jack said,equal pressure is almost more important than the number itself.for a stock evo,140 is fine,but also look at oil comsumtion,and general running of bike to let you know when internal work may be needed
     
  10. Sport40

    Sport40 Member

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    Thank you everybody.

    This winter I remove and change only the cam shaft with his bearing and pushrods.

    I replace the actuel cam shaft with an Andrews EV27.:small3d006:

    Cylinders will wait a few miles :s