Carb Problems

Discussion in 'Mechanic and Repair' started by Likestomow, Apr 7, 2005.

  1. Likestomow

    Likestomow LawnSite Senior Member
    Messages: 997

    I’m having problems with all four of my string trimmers (3 Kawasaki + 1 Stihl). Sometimes they are hard to start cold, and hard to start hot. Sometimes they will hardly keep running. I had the carb rebuilt on the Stihl last week, but it’s giving me a fit.

    The Kawasaki’s are still a few weeks less than a year old, but I’m told that carb problems aren’t warranted, so I’ve been thinking about taking the carbs apart myself. Are they that hard to clean?

    I started them all up today, let them run (they ran pretty good cold) and sprayed carb cleaner into the intake. They stumbled a bit then resumed normal RPM's. I didn't think this made much difference.
  2. vipermanz

    vipermanz LawnSite Bronze Member
    Messages: 1,773

    carb's arent hard to get clean, take it off the machine and take it apart on a piece of wax paper or cardboard so you can see all the parts
  3. Smalltimer1

    Smalltimer1 LawnSite Bronze Member
    Messages: 1,223

    A carburetor is not very hard to take off and apart to clean.

    There are several problems that can occur with 2 cycle engines:

    1. The carburetor can become pitted after a while and will give you fits trying to tune it right.
    2. If it has been adjusted too lean the screw tips could be blunted causing some roughness.
    3. The diaphragm may be leaking or torn causing improper atomization of the fuel.
    4. (Worst Case Scenerio), it may have a blown crank seal, which will let it run fine while sitting level but will throw the tuning off when it goes on an incline due to the seal opening up releasing the fuel mix, causing an oily buildup on the outside of the engine.
  4. KathysLGC

    KathysLGC LawnSite Bronze Member
    Messages: 1,345

    If your going to clean them you might as well buy a rebuild kit for them. For my Shin it cost $7.99. Put the pieces on a work space and open up your carb. Nothing will just fall out so don't be scared. You will see a screw hold a pin that is keeping your float on the carb. Remove that screw and remove the float. There is a spring with a needle attached to it. Your rebuild kit will have a new one so just remove that and keep it aside together so you know how the new needle sits. (once you do one there are all basicaly the same). If you can find the high/low needle turn them in clockwise until they seat but could the turns in 1/4's so you'll know where they where at. Write them down and remove the needles. Now use a good carb cleaner and soak it. If you have small pipe cleaners you can use that to help scrub out the holes. Thats basicly it for a basic carb which on a trimmer I think they're the same. Do you know if this is a Walbro carb?

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