Ben, that flapper may have been the metering diaphragm I was talking about? Any way give it a try and see what happens.... There is the senario that says... one of your inlet holes is normally plugged ( under the welch plug) and you are adjusting your needles to compensate for that.... and when the debris floats out of the way... your rich.. A way to check is to look at your needle adjustments... they should be somewhere in the 1.5 turns out vacinity. If its a lot more.. that tells us something important. They may be less like 1.125 or so. thats ok.
Flypaper. Congrats on your retirement!!. Hopefully you can now just have fun!!
BTW after I left Homelite. I went to work for the USGovt. testing chain saws for their Kickback energy in an engineering lab.. where I still am lol!!!!!!
Regards BobH.