Thanks for all the help SmokinJeff. Any idea what size the nipples are? 1/4" / 3/16" ?
Vacuum leak would likely contribute to low gas mileage too, right?
I'm getting 80-90 miles to a tank.

I swear, someone took this bike apart and half-assed threw the pieces back together as quickly as possible.

 

3/16 sounds about right. S/B the most common vacuum line size.

I don't know about the gas mileage thing. The extra, unmetered air would lean things out generally.

 

I took apart and cleaned the carbs proper, the jets were crazy clogged.. it runs so much better.
The difference in power between the high RPMs before and after is insane, it'll get to 95 with ease.

Another question, when I'm at a reasonable speed (50+mph) and I get on the throttle there is a very audible hissing sound. Any ideas?

 

Any ideas about the hiss? Is it normal?

 

No idea about the hissing but the top speed thing, my buddy was having a very similar problem with this zx6r and it was a hose that wasnt connected (i wanna say to the airbox?) I am not fully sure as it was not my bike, but take off your tank and check that all your hoses are properly connected and dont have holes or anything. Just my 2 cents

 

So I finally got everything sorted out.
This is my first bike, so I wasn't really sure what to expect as far as things 'running right.'

After I cleaned my carbs, performance was markedly improved, and I thought all was well.
... and then I took it to a mechanic, just to have the tires changed.
When I picked it up he told me it was running on two cylinders .

So I got home and verified it was running on two cylinders.
I checked for spark - good.
A friend of mine insisted it was the carbs, that two of them were so clogged there was no fuel going to cylinders 2 & 4... I cleaned carbs 2 & 4 again, overly thorough this time. They really looked spotless.

Went to start it up and nothing.

Right when I was about to give up for the night I decided to look at the spark plug wires.
I took them all off and noticed that I had two wires marked for cylinder 2 and two for cylinder 3.

Searched the forum and found they weren't hooked up right, left coil was connected to 1&2 right to 3&4.
Problem was I didn't have the wire for cylinder 1 and none of them were long enough for me to hook them up right.

I picked up a used wire today and couldn't wait to get off work and finally have it running right. I installed the plug wires correctly and.... nothing. Wouldn't start at all.

At this point I'm very discouraged.. I figured I wasn't going to be able to fix it myself.
Went back inside, got on the computer, and I was about to leave the forums when I noticed the left coil is supposed to be a Blue/Yellow wire, and I remembered mine was hooked up Yellow/Blue. The coils were wired in reverse.

All I can say is WOW, I did not realize what this bike was capable of.
This forum is invaluable. Thanks!
And a big FU to whoever put this bike together.

 

Damn, lol, what a bunch of fun! So I assume you got everything corrected and its now running well? Good to hear you sorted everything out.

As far as the hissing sound, I see where you say that it starts with any throttle at 50mph; and my question for you is what gears does it happen? My 96 (23k mi.) makes a bit of a hissing noise whenever i am in 6th gear with any throttle. I wonder if in my case its just tranny noise, being that 6th gets most of the miles on a road bike.