Help! Kohler 25 died, turns over but no compression

Discussion in 'Mechanic and Repair' started by Federal Lawn Company, Aug 26, 2011.

  1. Federal Lawn Company

    Federal Lawn Company LawnSite Member
    Posts: 91

    Any ideas where to start looking for problem? Symptoms are like a broken timing chain would cause...just died suddenly, spins over freely with the starter, but acts like no compression (resistance). Happened late yesterday, so I haven't had a chance to investigate it yet. Any help greatly appreciated!

    --David
     
  2. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    Some engine #'s would help....
    Pull the sparkplugs and check to see if the pistons are moving.
    Check compression
    Remove valve covers to see if the rocker arms are moving
    Any oil in the engine?
     
  3. Federal Lawn Company

    Federal Lawn Company LawnSite Member
    Posts: 91

    OK, I got all my stuff ready for the hurricane and checked it. It appears to be out of time....(no pun intended!). When I crank and engage the PTO, it attempts to spin the blades for a second...pistons are moving...crank is turning going into the PTO clutch..got spark...sprayed ether in carb....no attempt to fire. Any idea if it could have jumped time somehow? It there maybe a gear with a shear pin? I've looked thru the entire Kohler manual online and it doesn't show anything. I feel better, 'cause I was thinking a busted crank....but I don't see any red roses blooming out of the thing yet *smile*. Any advice is greatly appreciated....and yeah, I REALLY need another 60" for backup. I have a 36" Wright Stander with a 17 Kawi that I don't even use...other than with a barrell strapped to it to pick up flowers and trash at the HUGE cemeteries I cut. Anyone have a decent 60 with, say 1000 hours they'd like to trade? Stander has like 150 hours, 80 percent of them run like a Segway without the blades running. I put the SECOND set of blades on it that it has EVER had this spring....but I don't have any small gates to get thru any more...all commercial BIG stuff. Oh yeah...the tag is ripped off the motor on the Exmark, and I've got it written down SOMEWHERE, but I can't lay my hands on it at the moment....but it's a 25 Kohler Command on a (I think) 2007 Exmark...like 1600 hours.
    --David
     
    Last edited: Aug 26, 2011
  4. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    Check the compression with a gauge...
    Remove the valve covers to see if the rocker arms are moving.
    If all is good, you may have a broken crank gear....Which means a new crank and camshaft.
     
  5. Federal Lawn Company

    Federal Lawn Company LawnSite Member
    Posts: 91

    I figured if there wasn't a shear pin, that's what I'm probably looking at (can I throw up now?). I still haven't seen any pics or diags, so I have no idea what I'm dealing with for sure, but it couldn't be anything else that I can imagine. I appreciate the input....I'm no super mechanic, I'm a grass cutter, YOU HEAR ME!?!?! (snicker).

    Regards to you, Sir,

    David Innis
    Newport NC
     
  6. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    If you have a on-line manual you have all the pics and diagrams you need with step by step instructions, Just read the manual. If you don't understand something I'm sure our buddy Slapper will help you out !


    Oh..... I fixed this for ya David..... *pun intended*

    Good Luck
     
  7. Federal Lawn Company

    Federal Lawn Company LawnSite Member
    Posts: 91

    He he he! Thanks, Rob, I appreciate that! I think!?!?

    --David
     
  8. Floridalandcare

    Floridalandcare LawnSite Senior Member
    from Tampa
    Posts: 314

    I have a 27 kohler that was doing the same thing .When the machine was shut down and right before it stops it would kinda run backwards for a second,( anyone know why this happens?) then the next time it was turned over it would just spin like it had zero compression , after about 10 seconds of turning it over you could hear it getting a little compression and it would fire right up . I took it to a mechanic and he told me: first i was running the wrong oil : second when the engine spun backwards it was causing the lifters to pump up and hold the valves open . I completely rebuilt this motor , new lifters , rings , valve job , cylinder honed and sometimes it still does it .
     
  9. piston slapper

    piston slapper LawnSite Platinum Member
    Posts: 4,240

    The relief valve in the oil pump may be sticking. If you have too much oil pressure the lifters will hold the valves open.
    Posted via Mobile Device
     
  10. Federal Lawn Company

    Federal Lawn Company LawnSite Member
    Posts: 91

    Thanks for all the advice, Guys. I've either got a bent valve or busted camshaft (at least), and I don't have the time to mess with it...SO far behind. Especially since this Hurricane thing, this place is a disaster. I'm gonna go buy a new PZ 6034 Husq tomorrow if the dealer gets his power back on, and I'm just gonna replace the engine on the Exmark this winter. I need another 60 anyway, and I guess I'm being forced to make the move. Easy come, easy go....except for the easy part! Regards to you all.....

    --David
     

Share This Page