Compression 30 hp KOhler spec

Discussion in 'Mechanic and Repair' started by newblade, May 5, 2007.

  1. newblade

    newblade LawnSite Member
    Messages: 162

    What should the compression be on a 30 hp kohler when it is new, I checked mine to see how it was.

  2. Bill Kapaun

    Bill Kapaun LawnSite Senior Member
    Messages: 964

    You really can't get an accurate reading because the ACR holds the exhaust valve open too long at cranking speed. I'd venture to guess a slight difference in crank speed would have an effect.
  3. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    As Bill stated there is no accurate or set compression reading due to variances with ACR's.

    If a leak-down tester is not available a compression test will give some info. of the condition of a engine.

    Engines with/without ACR should have at-least 60 lbs compression to start and at that low reading could be harder to start.

    A compression test on a twin cylinder engine w/wo ACR can give a good idea of any major problems by the variance between the cylinders (cylinder balance). For example; If one cylinder tested at 180 lbs. and the other tested at 110 lbs. one could be safe in thinking there is a problem with the low cylinder.

    That's where the leak-down test comes in, To determine what the problem may be, Valves, rings or blown head gasket.

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