I'm working on a string trimmer currently whose adjustment screws are not labeled - or the labels have worn off with time. :) For reference, the carb is a Zama. It seems to me that there is a standard protocol on which adjustment screw is which on diaphragm carburettors.

From my memory, the L screw (low-speed jet) is closer to the engine block, and the H screw is usually closer to the air filter. Can anyone confirm or debunk this?

  • 1
    I know you're trying to make this generic, but really if you'd like specific help here, giving us a carb and/or engine model number, plus the make of the trimmer you're working on, we'd be able to answer your question a lot easier. Pictures would be an added bonus :o) Apr 11 '17 at 17:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.