Is this gash in choke circuit normal?

Sorry, I feel like i'm back here every 5 mins with a problem! I've got a set of 4th gen carbs from a breakers which looked in OK condition, but the choke plungers on carbs 3 and 4 were badly stuck. Once out I wanted to test the circuit was clear, so I secured a tube around the jet in the bowl and shot some carb cleaner down it. Nothing made it up the passage to where the plunger would normally sit, and I noticed this gash down the outside of the channel where the jet feeds it. It's biggest on carb 4 with similar (but smaller ones on the other carbs that i've checked.

Is this normal?

 

It's just a remnant of the machining process. Kinda looks like a landing to center / hold a drill process perhaps. Don't sweat it.

 

Hmm i've just given them an unsophisticated blow through and air comes out of both the gash area and the other end of the choke passage (where the plunger would be). However it's a feature of all four carbs (including the ones with functional choke plungers), and i've checked on one carb of my other set freshly removed from the bike - so it must be a design feature, I just have no idea of the physics. Hey ho.

 

Weird. Oh well.

 

This feature is also present in the earlier carbs. I suspect it's there as an air bleed vent to prevent an air bubble blockage of the "choke" circuit. When I clean the carbs I make sure to block this hole with a finger to ensure that the passage is open to the rest of the circuit.