Kohler Command 23 in Lazer Z puking, burning oil.

Discussion in 'Mechanic and Repair' started by 12and24, Oct 7, 2013.

  1. 12and24

    12and24 LawnSite Member
    Posts: 2

    Hi guys, thanks for taking the time to read my post.

    A month ago I bought a 2004 Lazer Z 60" AS. It was a craigslist basket case but for $800 I figured I didnt have much to lose. Machine has under a 1000 hours.

    Previous owner told me he burned a valve on the "left" side as you stand behind it. He repaired it and kept mowing ( he was a residential user.).
    Mower starts puking oil and loses power. He runs it until it wont run anymore.
    I tear it down. "Right" side has burnt exhaust valve and blown head gasket. I Lap in a new valve and put togather with new head gasket. Machine starts easy and runs great. Tons of power and not much will slow it down. Changed the oil..2 quarts of Valvoline 10w30 and a napa 1348 filter. Starts to smoke some. Smoking gets progressivly worse and goes through 2 quarts of oil mowing my 2 acre lawn. It eventually fouled the plugs. The Left bank was worse then the right. It was also pushing oil out both crankshaft seals. I thought I had the excess crankcase pressure problem fixed with the head gasket. Cylinder on the right looked good with no ridge at the top, even the original crosshatching was visible if you looked hard enough. Compression was 150 and 160 left to right.

    The only thing I havent checked is the breather and reed valve I hear people talking about.

    What do you guys think?
     
  2. grobinsonpa

    grobinsonpa LawnSite Member
    Posts: 101

    Hello,
    Yes, it sounds like the reed valve / breather valve is probably broken off. I had the same problem in a Kohler Command 18 hp. I did the same repairs you did and it still smoked and pushed out oil. The reed valve on one side had broken off. It is so small, you can miss it very easily. I can't remember if you can access that by removing the valve cover or you have to pull the head. You got a great buy on that mower. I have the same mower in a 2002. It now has 2000 hours and is a very good reliable machine. The 23hp has ample power for every normal cutting job. If you are dealing with very high overgrown grass it will struggle. Best of luck with it. George
     
  3. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    grobinsonpa ....you may be right...
    A broken reed will cause oil usage....not sure it would make the engine use 2 qts in a hurry ???
    Im guessing the engine has been run low on oil more than a few times and the oil rings are situck or worn out..
    With oil blowing out of the top and bottom seals...the engine prolly overheated from running low on oil...cooking the seals..
    36....(12plus24) ... it may be time to open up the engine and fix it right...
    BTW...the reed valves are between the lifters ...ya gotta pull the heads to see them..
     
  4. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    My boss told me to check out a mower similar to yours...thinkin of buying it...
    1999 lazer zhp...belongs to one of the crew leaders...
    I sent it out on our worst crew...it didnt run long before oil was leakin everywhere...loose oil filter...purolater no less...
    They put it back on the trailer....I changed the oil and filter and ran the engine...
    Oil was blowing out of the breather hose and completely saturated the brand new air filter...
    Checked engine vacuum...12 in vacuum...should be around 2 to 4 in...
    Checked compression...Cyl #1 175 psi....Cyl #2 135 psi...Time to look inside..
    Removed the heads ..reed valves ok...cylinder #2 scarred up...
    It ingested small metal pieces of the broken muffler baffles..
    Hps use a muffler extensiion pipe that looks like a snorkel..this piece was blocking the pipe,,
    Needs a shortblock and a new muffler.....
    Ya Never Know....

    IMG_0430.JPG

    IMG_0432.JPG
     
  5. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    Just a word to the wise....
    Dont try to sell any used eqpt to my boss....
    You may get it back in a box....long before you see the money...
    I really didnt want to add a 14 year old mower to the fleet anyway...no matter that it looked pretty new...
    Old stuff just breaks when you push them 50 to 60 hours a week...
     
  6. 12and24

    12and24 LawnSite Member
    Posts: 2

    Thanks for the thoughts guys.

    As far as the reed valve goes, I cant see it between the lifters..It is a horizontal shaft engine and not a vertical shaft if that makes a difference. I'm going to run it a little more, check oil pressure and if thats good, pull engine, put it on the bench and tear it down. Will hone cylinders and re-ring and new gaskets and seals. I've rebuilt quite a few engines and rebuild reefer compressors for a living so should be an easy project. Big thing now is to located a decent workbench for my garage so I can have a place to work as I still havent finished moving into my house yet.

    My handle is a refrence to my 2 rusty dodge trucks, 1 with a 12 valve cummins, the other a 24 valve.

    Thanks for all the help so far...Any Must dos or things to address while I have it apart?
     
  7. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    Yeah....there is a difference....
    The reed valve on Horiz.engines is located atop the engine...under the plate with 4 bolts..
     

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