Kohler 173cc engine will only run at full choke

Discussion in 'Mechanic and Repair' started by dansikes, Sep 24, 2009.

  1. dansikes

    dansikes LawnSite Member
    Posts: 8

    I have a 2008 lawn mower with 173cc Kohler engine, it will only run with the choke all the way on. I pulled the carb off and cleaned it and it still requires the choke to run. Any advice? :hammerhead:
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024

    Are you sure the main jet is fully open ? It's in the center of the carb where the float bowl retainer screw threads in.
     
  3. dansikes

    dansikes LawnSite Member
    Posts: 8

    I don't know how to check if the main jet is open or not. I saw the threaded shaft where the screw is in the center. I did not mess with that screw. If I take that screw (main jet) out should I remember how many turns to remove the main jet?
     
  4. JConner

    JConner LawnSite Member
    Posts: 174

    Try running it and spraying carb cleaner around all of the exterier of the carb without getting any in the main opening. if the motor sudenly dies then you have a air leak and thats what it sounds like is happening. When you have to run the motor on full choke it generaly means you have an air leak meaning choke to get more fuel to air ratio
     
  5. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    No, Just remove it and make sure it's fully open then re-install snugging it tightly.

    While a air leak can cause a engine to lean out and hunt/surge, It's not likely to require FULL choke to keep running unless the carb/intake is about to fall off.
     
  6. VegetiveSteam

    VegetiveSteam LawnSite Senior Member
    Posts: 297

    Are you getting a full flow of fuel from the fuel tank? There could be some debris slowing the flow causing the problem.
     
  7. rm25x

    rm25x LawnSite Member
    Posts: 187

    If it has a vacuum fuel pump it may have died on you causing the carb to not get any fuel unless you put the choke on causing more of a vacuum to draw the fuel from the tank.
     
  8. VegetiveSteam

    VegetiveSteam LawnSite Senior Member
    Posts: 297

    No fuel pump on this engine.
     
  9. dansikes

    dansikes LawnSite Member
    Posts: 8

    Tried spraying carb cleaner while it was running. The cleaner did not affect the engine at all. The fuel line appears to have a good flow of gas with the cap on and off. I think I might need to remove the main jet and clean the entire carb again. Thanks for all the reply's!!!
     

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