1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Strimmer starting issues

Discussion in 'In the Garden' started by ipbr21054, 17 Aug 2021.

  1. Burnerman

    Burnerman

    Joined:
    7 Feb 2008
    Messages:
    23,073
    Thanks Received:
    4,483
    Location:
    Northumberland
    Country:
    United Kingdom
    The metering lever, at rest, is designed to be parallel to the machined face of the carb, where the metering diaphragm sits.
    On a four stroke engine, induction is caused by piston descent alone - however on a two stroke engine crankcase pressure can be used to help fuel pumping....Inducted fuel passes into the crankcase before being transferred above the piston where it is fired.
    You may find that any grooves are there to allow carburettor breathing in your situation.
    In either case, study any drillings on the inlet manifold and mating carburettor face, and refer to the truth marks on the original gaskets to make sure everything is in the correct order.....it’s really all you can do.
    John :)
     
  2. Sponsored Links
  3. JohnD

    JohnD

    Joined:
    15 Nov 2005
    Messages:
    73,610
    Thanks Received:
    4,247
    Location:
    Crossgates, Europe
    Country:
    Cook Islands
    How many fuel jets does the carb have?
     
  4. Burnerman

    Burnerman

    Joined:
    7 Feb 2008
    Messages:
    23,073
    Thanks Received:
    4,483
    Location:
    Northumberland
    Country:
    United Kingdom
  5. ipbr21054

    ipbr21054

    Joined:
    13 Nov 2008
    Messages:
    945
    Thanks Received:
    5
    Location:
    Avon
    Country:
    United Kingdom
    With regards mine in respect of jets I have a threaded screw which is pointed at the end. I use this when revs are full and turn it left / right etc.
    I believe there is also a screw at the top which passes down through the part you can see rotate through the Venturi when the throttle lever is operated.
    So I’m my case 2 ?

    I’ve only touched what i would call the mixture screw.
     
  6. JohnD

    JohnD

    Joined:
    15 Nov 2005
    Messages:
    73,610
    Thanks Received:
    4,247
    Location:
    Crossgates, Europe
    Country:
    Cook Islands
    If there is a "starting" jet, or a "slow running" jet, it might be clogged. You would not notice once the machine is running.

    On a bike, it can mean difficult starting, and stalling at traffic lights.

    These jets are also smaller than the main jet, so easily blocked with sediment, it may recur after a winter lay-up.
     
  7. Rekusu

    Rekusu

    Joined:
    8 Mar 2010
    Messages:
    190
    Thanks Received:
    0
    Country:
    United Kingdom
    My gx25 carb only has on jet and one metering lever. The metering lever has to be correctly set but it is quite a large range (1.18 - 1.50mm according to the blurb)

    However, I did find another Youtube vid, which although it did not provide any new info, it did jog my memory that I may have the metering diaphragm below the gasket when in this vid, it was above. Something else to check and ad to my dismantling experience.
     
  8. Sponsored Links
  9. Burnerman

    Burnerman

    Joined:
    7 Feb 2008
    Messages:
    23,073
    Thanks Received:
    4,483
    Location:
    Northumberland
    Country:
    United Kingdom
    The diaphragms go against the machined alloy body of the carb, the gasket goes above that on the other plates or insulators (as they are called).
    John :)
     
  10. ipbr21054

    ipbr21054

    Joined:
    13 Nov 2008
    Messages:
    945
    Thanks Received:
    5
    Location:
    Avon
    Country:
    United Kingdom
    Please see photos of my screws.
    The blue screw is what i adjust when throttle held down.
    The red screw ive never touched.
    This i assume must be the part that allows fuel in at start up ?

    Please advise what i need to do in order to check it or adjust it so my starting issues can be resolved.

    Thanks
     

    Attached Files:

  11. Rekusu

    Rekusu

    Joined:
    8 Mar 2010
    Messages:
    190
    Thanks Received:
    0
    Country:
    United Kingdom
    "The diaphragms go against the machined alloy body of the carb, the gasket goes above that on the other plates or insulators (as they are called)."

    Now not sure what I have done but think I have the diaphragms either side of the metering body. Is that correct? But this vid () shows the gaskets wither side of the metering body. Which is correct?

    Sorry to hi-jack the thread; as the original post, these things are not rocket science but they sure as hell are difficult to get right.
     
  12. lostinthelight

    lostinthelight

    Joined:
    11 Feb 2016
    Messages:
    3,113
    Thanks Received:
    597
    Location:
    monmouthshire
    Country:
    United Kingdom
    The vid here is correct for what goes where..
     
  13. Rekusu

    Rekusu

    Joined:
    8 Mar 2010
    Messages:
    190
    Thanks Received:
    0
    Country:
    United Kingdom
    Thank you; very useful and will double check how I have fitted them.
     
Loading...

Share This Page