Pinch test does nothing for the low end.

Easy test on the low end.

Run up the motor, get the high right, first. Use the pinch test for the high.

Idle the motor down, let it idle for 10 seconds, or so, then go to WOT. What does it do????? Burble, cough and choke then slowley come up to max RPM? If so, the bottom is too rich. Only ajust the low in tiny amounts, 1/8 turn at a time or so. If the motor sounds like it is starving for fuel or dies, the bottom is too lean.