Here's the way we do it.

Start the engine at about 1/4 throttle and allow it to run for a minute or so.

Slowly come up to full throttle and work the hs needle in until it's about 2 or 300 rich side of peak. Let it run for a minute or so.

Reduce throttle to idle of about 2200 to 2400 rpm. Leave it at idle to see which way it goes. Gradual increase in rpm indicates lean, if it does this, richen regulator and possibly richen air bleed.
If too rich at idle make opposite changes.

When it 's about right, check transition from low to high. Adjust regulator for good transition.

BEFORE DOING THIS, CHECK THE VALVE CLEARANCE WITH ENGINE COLD. SHOULD BE .003", BOTH VALVES.