Red: Roxy Carb Saves the Day

First checked the throttle cap and saw that the ferrule had come off the housing.  Could that have been causing the issue by letting in extra air somehow?

After fixing and tightening that up, started the engine and it would not hold idle at all, no matter how dialed in the air screw was.  So the throttle cap was indeed affecting it somehow.

Then did what I had planned to do anyway, which was to swap that Sheng Way out entirely for the carb just pulled off Roxy (CS90C).  It would have the extra benefit of keeping the vintage Keihin in good running order.

Swapped it out (which meant it joined its original intake, also pulled from Roxy).  Started her up, and she ran like a champ.

Upstairs, pulled the Sheng apart to find that familiar white residue on the idle jet.  And even after two rounds in the ultrasonic, it looked like the big hole was jammed up (couldn't see daylight through it at all).

So knowing all this, it must have happened this way:

1. When I swapped Sheng #1 for Sheng #2, I must have disturbed the ferrule and created that air leak.  That would explain the racing idle that was not fixed even when I swapped back to Sheng #1 as a test.  It also explains why adding the intake gaskets didn't help.
2. The clogged slow jet in Sheng #1 also explains why it always needed so much air screw to run at all.
3. When I fixed the ferrule today, it stopped the air leak, but the air leak was the only thing actually allowing the carb to run at idle at all.  With the air leak gone, the clogged slow jet came into effect.

Also swapped out old taillight bulbs with LED on both Roxy and Ivy.  (Ruiandsion 1157 LED, $11 Amazon)