Needle Jet / Main Jet at idle

Sorry folks - this question is sort of a generic one. This is not a KZ question specifically, but I respect your knowledge a lot (I used to be on here back in 2008 when I restored a KZ440)

My question is this: Should fuel come out of a CV carburetor's needle jet/main jet at idle?

Or should absolutely zero fuel come out of the needle jet / main jet at idle?

streamable.com/e/puxomp

Considering how high that slide sits when the engine is off, I suspect it is designed to pull fuel through the main at idle. Just my suspicion, though.

How does it run with the airbox?


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