PW22 carb rebuild. Is there an o-ring on the air screw?

[onchiman]

I'm rebuilding (cleaning) a PW22 carb on my '63 CA77 Dream. Upon disassembly I noticed that there is no o-ring on the air screw. The diagram for this model indicates there is supposed to be one and it's Honda part number 16175-260-004 and is supposed to be 2.8mm. Well I measured the opening for the screw and it doesn't seem as though a 2.8mm OD o-ring is going to fit, it's too large. I assume the o-ring goes into the carb body first, then the spring then the screw? Is there a source for these o-rings as they seem to be discontinued by Honda.

[LOUD MOUSE]

Some of these carbs DON'T use that part. If it's not there don't add it. .............lm

I'm rebuilding (cleaning) a PW22 carb on my '63 CA77 Dream. Upon disassembly I noticed that there is no o-ring on the air screw. The diagram for this model indicates there is supposed to be one and it's Honda part number 16175-260-004 and is supposed to be 2.8mm. Well I measured the opening for the screw and it doesn't seem as though a 2.8mm OD o-ring is going to fit, it's too large. I assume the o-ring goes into the carb body first, then the spring then the screw? Is there a source for these o-rings as they seem to be discontinued by Honda.