kohler engine

Discussion in 'Mechanic and Repair' started by briggs33, Apr 16, 2008.

  1. briggs33

    briggs33 LawnSite Member
    Posts: 28

    im having trouble wth a 25hp kohler command engine. one of the cylinders doesnt fire. i checked spark its perfect. not sure about the gas but on the plug it seems to have enough. i did compression check it and the bad cylinder had 110psi and the good had 120 but i but a liitle oil in the spark plug hole on the bad cylinder and it rose to 130psi so i think its the rings but not sure?model # CH15S SPEC # 68503 Family # SKH725U1G2RA any suggestion welcome!
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

    I'm going to guess the CH15S is a typo.....Remove the valve cover from the weak cylinder and check for backed off rockers or a bent push rod.

    You can still get compression even though the valve(s) are not opening, 10#'s difference between the two is not enough to cause that one cylinder to be dead.
     
  3. MowerMedic77

    MowerMedic77 LawnSite Bronze Member
    Posts: 1,164

    Check for a bad intake gasket, spray carb spray around the manifold/head mating surface while its running and see if your cylinder picks back up. Have seen many units with spark and compression but running so lean on one cylinder as to give a dropped cylinder effect.
     
  4. briggs33

    briggs33 LawnSite Member
    Posts: 28

    thats what it was it has two bent push rods along with the valve coming out.on the exhaust valve. i know a guy who is going to fix it so that taken care of but does anybody know the torque specs for this motor? i need the head the rocker arms side cover and what ever else that is torqued thanks
     
  5. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,023

  6. caseymax

    caseymax LawnSite Member
    Posts: 16

    Cylinder Head
    Cylinder Head Fastener Torque
    Hex Flange Nut - Torque in Two Stages ... first to (150 in. lb.)
    finally to (300 in. lb.)



    Head Bolt - Torque in Two Stages . first to (200 in. lb.)
    finally to (370 in. lb.)
     

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