In article ,
"Sam S." wrote:

Mercury vacuum gauges, as used on multi cylinder motorcycles.

Its basically 4 rod vacuum gauges affixed side by side. You attach the line
to the provided vacuum ports on the carbs (behind the throttle plates), then
while running the engine, adjust the plate(s) so that all 3 gauges read the
same.

Adjust curb idle as needed...done.

Check you local motorcycle tool shop.

Sounds easy enough! Thanks!