I rebuilt my carbs on the weekend, and found out why they're called springs.

The Bypass Air Cut-Off Valve (on the left carb only) had been
destroyed/disabled by a previous owner, so I need to find a new or used
replacement.

And...
I lost a spring. (shame) Ihave crawled around on my hands and knees looking
for it, but no luck. It is the spring that controls the lever that runs to
the square doohickey on the side of the carb. It's about 2 inches long and
1/8' in diameter, expanding to about 1/4" at one end.

Peter Williams
73 Westy
California or Bussed