Stihl KM 110R Carburetor problems

Discussion in 'Mechanic and Repair' started by Chencho, Jan 25, 2013.

  1. Chencho

    Chencho LawnSite Member
    Messages: 23

    I have a KM110R that starts up and Idles. Starting can be somewhat rough but after a 4-5 pulls it manages to start. After I get it warmed up and try to use it I have issues...

    It doesn't rev up properly. It seems to bog unless I play with the throttle. After I get it up in RPM's it will run at full throttle for a few seconds and then started to bog down and shut off if I hold the throttle down. If i let the throttle go then it doesn't shut off and idles.

    What I have done...I tuned the carb to factory settings and nothing. Cleaned the magneto and have brand new spark plug and new filter. I have even played with the tuning with all sorts of combinations and nothing seems to get better. Only worse. Fuel lines are healthy and brand new gas. Only thing I haven't done is take apart the carb or Clean the head of the engine.

    Anyone have any recommendations?

    Thanks in advanced
  2. dboyd351

    dboyd351 LawnSite Bronze Member
    Messages: 1,124

    Clean the spark arrestor screen and exhaust port first, if that doesn't do it, adjust the valves.

    IRRITECH LawnSite Senior Member
    Messages: 999

    I have had some success with the stihl decarbonizer. If the unit is older and you have never done this try it. And like dboyd said adjust the valves. Also if you have a bunch of grease and dirt on and around the carb look at the gasket between the insulator and head. I have recently replaced 2 of them one KM110 and an FC90.
  4. piston slapper

    piston slapper LawnSite Platinum Member
    Messages: 4,337

    I have about 20 of the 4mix handhelds...they hold up pretty good...
    At the first sign of trouble I check the sparkplug...then the valve adjustments...
    Those 2 things fix most of the problems...
    An easy way to check the isoplate for leaky gaskets to grab ahold of the breather cover while it is running.and try to twist it back and forth...side to side...if the engine speed fluctuates..gasket is leaking..
  5. Landrus2

    Landrus2 LawnSite Fanatic
    Messages: 5,050

    Stihl decarbonizer is that like mechanic in a can:laugh::laugh::laugh::laugh:
  6. herler

    herler LawnSite Fanatic
    Messages: 5,139

  7. windflower

    windflower LawnSite Bronze Member
    Messages: 1,109

    I had a similar issue with the same machine. It would idle fine but throttling up became progressively more difficult until it wouldn't at all no matter how long I let it warm up. Exhaust was clean as was the air filter. Carb looked good and engine wouldn't rev up on ether. Replaced the ignition module. Runs fine now.

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