Mixture screw on GXH50 carb: adjustment-reducing design

Discussion in '4-Stroke Engines' started by Max-M, May 5, 2014.

  1. Max-M

    Max-M Member

    I've got an ongoing bogging problem on my very new Honda GXH50 engine. I've tried all kinds of fixes (less-restrictive fuel filter, cleaning idle jet, etc.). But I think the problem might be staring me in the face. My engine's carb has a mixture screw that is designed in such a way that it can only move about 1/4 turn total. See the photo below.

    I imagine that the unmodified GXH50 engine running in an application that it was designed for (water pump, cement mixer) might be alright with that narrow range of adjustment.

    But on a motorized bicycle with a less-restrictive exhaust, a higher load placed on the engine, etc., it seems like that range is way too narrow to get the correct adjustment.

    Has anybody here ever modified such a screw to open up the range of adjustment? I think I'll probably cut off the protruding bit that the red arrow's pointing at -- my Dremel should work nicely on that.

    But I just thought I'd put this out there for your thoughts and advice.

    Thanks for any assistance.


    PS: See the second photo in my reply below.

    Attached Files:

  2. Max-M

    Max-M Member

    THIS full-range brass screw gives the range of adjustment that I want. (Just grabbed the photo off the internet.)

    View attachment 52804