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kohler 22hp head gasket issues

Discussion in 'Mechanic and Repair' started by willygee, Jan 30, 2008.

  1. willygee

    willygee LawnSite Member
    from MI
    Messages: 10

    Today I went to look at a used Bobcat 61" ZTR. The owner told me it needs a new engine (22hp Kohler) due to a head gasket problem. He claims to have replaced the head gaskets four times and every time they start leaking again. Is this a common problem after head gaskets are replaced by a "non professional" ? A local dealer has a nice used replacement engine but it has a smaller output shaft (1 inch). If I were to buy the used engine is there a PTO clutch that I could buy to make the 1 inch shaft work with this mower? He was able to start the engine, drive the mower around the parking lot, and engage the blades. The prices he is asking is very fair so I left a deposit. Any help would be greatly appreciated
  2. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029


    Click the link below and enter the engine numbers and download the service manual for this engine.


    It will give details on checking the heads and block for flatness, Also how to check the breather reeds. Four gasket changes means something is wrong or someone isn't doing something right. I have never had any of the countless gaskets I replaced come back blown again.

    If you get into the reeds, Remove them and check for any burrs in the block mating surface on the outer edge of the hole.

    I'm not sure about a clutch, You would need to take measurements of the old one.
  3. GravelyNut

    GravelyNut LawnSite Bronze Member
    Messages: 1,594

    Head gasket blowing on the head sounds like someone didn't check the head for flatness or torqued the head down wrong. 4 times is 3 times too many for something not to have been done wrong.
  4. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    No, I don't see Kohlers experiencing this problem unless that particular engine is a lemon and even then it's likely something along the lines of what's been said.

    On the notes of the shaft, I don't fool with shafts that are not the exact same specs as the one I need to get...
    I've replaced two or three engines in my time, and shaft and frame size are among the most important specs, you can compromise other things and then it can be a doable pita but my opinion is don't fool with the shaft.
    One idea would be to maybe see if your dealer would install it for you, likely cost you 50-100 extra in labor (not sure about parts) but that would be the only other option I would consider.
  5. willygee

    willygee LawnSite Member
    from MI
    Messages: 10

    Thanks for all the great replies. However I am seriously thinking of purchasing the engine I mentioned (the one with the smaller diameter output shaft). I will try to replace the head gaskets on the original motor but the engine already has 3600 hours on it so I will need a back up regardless. My plan is to use a lathe to drill a 1 inch hole through a piece of 1 1/8 inch round stock, then use a mill to cut a 1/4 inch slot the length of the piece, for the key way, and then finally replacing the original piece of 1/4 by 1/4 key stock with 1/4 x 5/16 key stock. After the piece is completed I am fairly confident that it should work to adapt the smaller shaft engine to the larger hole in the PTO clutch. I was wondering if anyone can think of a reason why this wouldn't work. Constructive criticism is welcomed and encouraged.
  6. themowerman

    themowerman LawnSite Senior Member
    from NJ
    Messages: 298

    I remember there was a service bulletin when this motor came out on the Ransomes BobCat machines. The head bolts were too long and Kohler came out with a head bolt kit. I don't remember how long ago this was but I want to say it was about 5 to 7 years ago. I painfully remember this as i had to do 20 plus units that were brand new. If I remember right...looking at the motor from the carb side it was the right cyl heads that were the first to leak. Maybe some of the older Kohler dealers on here can remember the service bulletin number and can help you out with the kit number. My mind is turning to mush as I get older.
  7. fly-4-fun

    fly-4-fun LawnSite Member
    Messages: 0

    Willygee, making a bushing for the shaft on the motor should work, I wouldn't just bore a hole with a drill. I'd drill to about 7/8", then use a boring bar in the lathe to finish the size to 1". You have to remember that the wall thickness on this bushing will only be 1/16" when you finish. (1 1/8" - 1" divided by 2 = 1/16") It should work, if the shaft on the newer motor is the same length as your old motor. Don't know if I'd do this on mower that was going to be used commercially, but for a homeowner it should be ok. My .02 worth.........

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