Rough running kohler command 20

Discussion in 'Mechanic and Repair' started by Westbrooklawn, Aug 12, 2002.

  1. Westbrooklawn

    Westbrooklawn LawnSite Senior Member
    Posts: 414

    I have a Walker GHS mower with a Kohler Command 20 engine. It has about 600 hours on it. It just started to run rough, lack power, spit, sputter, and occasional light backfire/miss while running......almost acts like it is partially choked. Is this a common problem with these engines? Filters, plugs, fuels, etc. have always been maintained properly.

    I am going to start by replacing the gas filter, air filter, and plugs. If this doesn't help where should I look next? This Problem started after some heavy mowing which really put a load on the machine. Is there a possibility of overheating problems......possibly burnt valves???

    Would appreciate any thoughts.
  2. olfrt

    olfrt LawnSite Member
    Posts: 48

    Start with the air filter and do one thing test run then to another to figure which one solves the problem
  3. Westbrooklawn

    Westbrooklawn LawnSite Senior Member
    Posts: 414

    Still having rough running problem with my Kohler 20 command on Walker 48" GHS. Spits, misses, light backfires while running, particularly at 1/2 to 3/4 throttle. I have replaced air filter, gas filter, drained and cleaned gas tank, and replaced plugs.

    What next?
  4. olfrt

    olfrt LawnSite Member
    Posts: 48

    was there water in the filter or the tank?

    You may have some water in the carb bowl.

    Check your seat switch especially if it happens on hills or slopes

    Check the throttle plate to see if the throttle cable is pushing the choke part way closed. I have seen the wire end catch the choke plate on the throttle/ choke bracket and move it.
  5. Westbrooklawn

    Westbrooklawn LawnSite Senior Member
    Posts: 414

    Thanks for the hints. I didn't see any water in the gas or the filter, although there was a lot of fine trash in the gas tank. It isn't the seat switch since it does it without the blade engaged. The choke plate position and linkage is O.K.

    Is it relatively simple to take this carb apart and get it back together? Maybe I should try that. Any additional hints would be appreciated.
  6. KenH

    KenH LawnSite Bronze Member
    from CT
    Posts: 1,622

    Shut off the gas, take the carb. bowl off, clean it out, and run some gas through the lines. This will get out any dirt, ets.
  7. thfireman

    thfireman LawnSite Senior Member
    Posts: 541

    I had a simular problem last year. I tried everything and then finally replaced the entire fuel line. It seems that the inside of the fuel line had collaped or become narrow and it was not letting sufficient fuel flow through. My mower would start and run fine for a minute and then start acting like the choke was pulled or it was running out of fuel. The new fuel line fixed it.

    Also you might check the needle and seat if you have not already done so. If the seat in the carb is bad it may load up with fuel.

    You may have already tried these things but thats what helped me.
    :) :D ;) :p :cool: :angel:
  8. edward hedrick

    edward hedrick LawnSite Senior Member
    Posts: 871

    Check the coils I have a 22 Koh on my scag same engine as 20hp

    tried filters and gas, turned out to be elec. check dealer
  9. TJLC

    TJLC LawnSite Bronze Member
    Posts: 1,308

    My 18 Kohler is starting to run rough once it gets good and hot, mainly after it gets hot and then I shut it down and start it up again. Then it acts like it's running on one cylinder. I don't know if this is the problem you are having or not. My dealer says it's probally the coils.

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