K2 Petcock Issue: In reserve position, fuel coming out of only one nozzle

[Bayou]

In reserve position, fuel is coming out of only one nozzle that connects to cylinders 3, 4. The nozzle that connects to cylinders 1, 2, not even a drip.

I took the Petcock apart, it looks clean. The rubber washer with 4 holes behind the fuel shutoff lever looks good too. Not seeing anything out of the ordinary.

Please let me know what I'm missing.

Thank you!

 

[Bayou]

Luckily, I got hold of a spare K2 tank with its own petcock; same behavior in that one too. In reserve position, fuel is coming out of the nozzle that connects to 3, 4. The other nozzle that connects to 1, 2 is bone dry. How does the fuel get to cylinders 1, 2? I'm at a loss because there is no fuel linkage between the two sets of carbs (1, 2 and 3,4).

I'm guessing one nozzle is for reserve and the other is for main/on? If yes, that still leaves my question unanswered.