KZ400 carb teardown (for real this time)

Ok we're going to try again. 746C is marked on the carbs. That makes them 1974. If we refer to the chart here, we see the standard jetting:

Here's an exploded view:

Another thing to be aware of is the butterfly screws are JIS. You can tell by the little dot on the heads. The best way to make sure you don't strip them is with a JIS screwdriver. Another option is to grind down the tip of a regular phillips.

Here you can see these guys. Top screw is 'vacuum plug' and it is removed when using factory carb synchronizers.
Bottom is 'pilot screw'. Before you remove it, screw in the pilot screw and note how many turns out it was. Factory starting point is 1.5 turns out, but it should be adjusted per the manual.

Here's the choke plug. Gods help you if it's stuck in there.

Primary and secondary air jets are 60/110. They were Keyster, so this carb has been rebuilt.

Standard jetting is 60 for the primary air jet and 100 for the secondary. The primary air jet goes into the hole closest to the screw hole.

These are called 'main air jet' and 'slow air jet' in the diagram above.

Needle jet with proper orientation. I use a chopstick to push them out.