I thinking the same thing?
I'm trying to get a low idle by closing the carb to much? right to the verge of dying..
How large should opening be when at lowest throttle setting.
could be I need to keep the carb open a little more and set the low speed needle???

Tonight I'll pick up an electric starter and do some more testing.

Now that I have the tach I feel more comfortable working on the engine as I dont yet know the difference between 2,000 rpm and 3,500 just by listening..

Thanks

Steve