2000 F9.9mshy air adjustment screw

Been fighting problems with this motor for years. Have not used it much but recently decided to get it going right. Put kit on carb, cleaned it and replaced diaphram in bottom that was leaking like the devil and hope that was 99.9% of my problems because that quarter sized part was 48$ after tax. i did not replace the air screw needle because i couldn't back it out. it screws out so far then runs out of threads and the head is still recessed where you cant grab it. now i am trying to adjust it (motor running very well) and not noticing hardly any difference no matter which way i turn it. i think i am seeing bits of the o-ring coming out around the screw head when i turn it. any advice appreciated. thanks

thanks for all the help. I used epoxy on the screwdriver and let in set up an pulled it right out. having trouble getting it to run now.

this air adjustment needle along with the diaphram in the bottom of the carb were my problems. The o-ring on the air needle was broken down and the orifice may have been partially or intermittently plugged by rubbery trash. this thing is running perfectly now. i have another problem i will start another thread.