Another CV 'O' ring question - KZ440

In rebuilding the CV carbs on my 1980 KZ440B, it became obvious that the last person to work on them never replaced an 'O' ring. Looking at the line drawings for these carbs, I see an 'O' ring specified for the plastic plug (the purpose of which I do not know). When I pulled those plugs out, there were again no 'O' rings. So far, I've just assumed that the book was right and the last tinkerer wrong. This time, I even have two small 'O' rings leftover from my rebuild kit, and kind of imagine that this is where they belong.

My question is, does anyone know better, or can somebody assure me that the two 'O' rings in the rebuild kit are indeed meant to tip those plastic plugs? Thanks.

The plugs are o-ringed to prevent fuel from leaking past.

I believe that plug is part of the pilot fuel circuit, preventing the pilot from recieving too much un-metered fuel.

+1
The same type of plug is in the CV 34 carbs for the 750 and you need the o ring on that plug. It covers the pilot jet which gets its gas via a line off the primary main jet.

My list of carb part websites:
www.nrp-carbs.com
www.motorcyclecarbs.com
www.carbparts.com
www.carbkitscapital.com
www.pjmotorsports.com
www.jetsrus.com
www.sportingforless.com/servlet/the-Carb-repair-kit/Categories
www.oldbikebarn.com/Motorcycle_Parts/Carb-Rebuild-Kit
www.cycleorings.com/

So, are those 'O' rings routinely included in rebuild kits? I'm hoping so, because otherwise I have 2 leftover (no carb genius here). I'm concerned that I can screw the process up totally if they're not supposed to go there. Thanks.