TOPIC:

KZ440. 

The nipples on the bottom of the carbs… is there supposed to be a plugged tube connected to them?  

In the pic, you can see the far carb has a tube coming down, and is plugged with a screw. 

The near carb has nothing, just the exposed nipple. 

The parts diagram shows open-ended tubes, but I’m just trying to sort out how things are supposed to be. 

  

Open ended overflow tubes.

wrote:

Open ended overflow tubes.

OK, so I can just T those together and run one tube down the bottom of the bike.  Easy enough.

As for that flathead screw on the side, is that a manual drain for the bowls?  Or some adjustment screw?

Yes and drain screw.

Right on 

The 1980 model year was the last year for overflow tubes.  In 1981 the overflow tubes were removed because they allowed gasoline vapors to escape the float bowl.  For the later year bikes the nipple is just for draining the bowls so there is no need for a tube attached to the nipple.

wrote:

The 1980 model year was the last year for overflow tubes.  In 1981 the overflow tubes were removed because they allowed gasoline vapors to escape the float bowl.  For the later year bikes the nipple is just for draining the bowls so there is no need for a tube attached to the nipple.

This bike's an '80.