I just got a ’63 JW up and running after it sat for a number of years and it had some carb issues to. It would run lean in the mid range and needed the choke tickled a bit to get it up to speed. After resealing the crankcase to eliminate any vacuum leaks and working on the reeds, I made sure the carbs main jet was clear by passing a 0.030" drill shank thru it. If it hesitates going thru the mid range now, I just open the low speed needle a bit to help it out and readjust the idle mixture when the motor slows down. This motor purrs with the needle about 1/2 to 5/8 of a turn out from gently seated. Any more and it floods out.

https://www.youtube.com/watch?v=Rxma7GI … e=youtu.be