Vacuum line routing

Yup, I was wondering what that big azz hose was connected to. I am not sure what that is about.

If nothing else, I should put a cap on it, correct?

The nipples on the manifold boots require a black plug that you can find on ebay or on Z1E.

There should be a nipple on one of the carbs, on the downstream side.  This is your vacuum source for the petcock.  If you don't have a vacuum petcock then this nipple should be plugged off.  You can plug it with a nipple similar to the ones mentioned above.

The other nipples on the carbs should be on the intake side.  These are to provide atmospheric pressure to the carb bowls.  (They are essential for correct carburetor function, which work based on the difference in pressure between the bowl and the carburetor throat.  Pressure in the throat is lower, and this is what draws fuel up the jets.)  These nipples should have a short hose on them that ends under the rear of the tank.  

All of the above applies to a non-smog head engine.  If you have a smog head engine then simply block off the ports on the valve cover and follow instructions above.

Hardrockminer,

Did you see that large vacuum port hanging down from the bottom of one of the carb holders? What is that thang?

That's the $64,000 question.  I have no clue.  I will be capping it off when I go out to work on it tomorrow morning. 

I live right on the border with Mexico, and it has been so friggin' hot that when I get home, I shower and become a couch potato.

Is there any way to tell if the air valve switch is good or not?  I've got it off the bike, but no sense putting it back on if it's part of the problem.  I've sucked and blown through the various openings on, but the vacuum nipple (4mm) is different.  I can suck on it, and I hear what sounds like a diaphragm popping inside, but it I don't know if it's supposed to open completely and allow air through or what.

Got the vacuum lines replaced and plugged the nipple on the head side of the carbs.  About 5 seconds of running with the choke, it didn't need it anymore and I have great throttle response.  I didn't go ride it since I had shorts on and I didn't want to change.

I started work on those horribly blued pipes.  I still have more polishing to do.

I did take my Suzuki out yesterday, but damn!  It's hot down here.