First, let it warm up.
Then run it up to WOT (wide open throttle) and set the highspeed needle.
You do that by opening it until the engine is obviously rich. Smoking exhaust and slower rpm sound.
Then bring it to idle and let it go. It should hold fairly steady for you to get bored and wonder how long you should be standing around wondering how long you should be standing around.
If it won't do that, THEN do a pinch test at idle.
If it did idle happily until you ran out of patience (ok, not that long)......
Slam the throttle wide open from that happy idle and see if it accelerates or chokes and dies.
If it stumbles or anything other than cleanly accelerating, THEN do a pinch test at idle.

Sorta like you said, but allowing for what might happen.