Stihl Blower & Weed Trimmer Repair

Discussion in 'Mechanic and Repair' started by moonrunner, Nov 30, 2006.

  1. moonrunner

    moonrunner LawnSite Member
    Messages: 1

    I have an 2-cycle stihl weed trimmer and blower that have recently seemed to have problems. The machines will start... but when I pull their triggers to get them going they seem to "bog" down and will not spin or blow very strongly. Sometimes they will even just shut off.
    They both require "mix" for fuel... and the fuel I use is good, clean, and I use the 50:1 ratio stihl engine mix at the right ratio of oil with gas.
    Any ideas on the problem?
  2. Total.Lawn.Care

    Total.Lawn.Care LawnSite Senior Member
    Messages: 840

    First things I would check would be the following:

    1. Air filters. Ensure they are clean and allow unrestricted airflow into the carb.
    2. Spark Plugs. Again, make sure they are clean and not gummed up or covered with crud. This could cause reduction of spark.

    Might need to replace both the air filters and plugs to endure they are not the problem. If those do nto fix the issue, I would ensure that the fuel filters are clean and you have good fuel flow.

    If those do nto fix the issue, then it is possible that you have some carb problems and they may need to be cleaned.
  3. dutch1

    dutch1 LawnSite Silver Member
    from Jayhawk
    Messages: 2,248

    I will agree that clean plug and air filter are necessary for superior running condition. However, the two most common problems that I encounter in 2 cycle products is carboned up anti spark screens/exhaust ports and varnished up in tank fuel filters. If, after checking the above four items, try adjusting the high and low speed screws counter clowckwise half a turn if the carb has them. If adjustment doesn't help I rebuild the carb. If no adjustment screws are present, the diagphram pump in the carb is likely hard and not capable of pumping proper fuel.

    There are other problems that can occur as well. I recently worked on an Echo BP blower with similar symptoms. Did all of the above with not a lot of improvement, although I did find trash in the fuel screen inside the carb. I suspected an air leak so with the unit running I sprayed down the carb gasket areas with carb/choke cleaner and the unit died. Found a hairline crack in the isomount between the carb and block.

    Just some areas to check out. Your mileage may vary.

  4. adameid

    adameid LawnSite Member
    from sydney
    Messages: 16

    moonrunner check if your machines have a spark arrestor.Its located will on the muffler. It may be clogged and blogging down your machines.

    let us know how you go

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