Unable to locate a rebuild kit

Hello everyone, I recently bought a 1980 kz750 Ltd that had been sitting for 2 years or more... If possible what are the top priority parts that need replaced? It does run, although leaks fuel, throttle lag, and rough idle. I removed the carbs cleaned them as best I could but didn't have a kit so I felt I was just wasting my time. I need a rebuild kit due to the previous owner stripping the main jet completely flat, float bowl g are all shot, need new o rings everywhere, and pilot jets. Any advice from experiences you've had would be appreciated. 

Also the front brake was broken when I got the bike I've since replaced the hand brake lever with a new one but can't get the bleeding correct. Thanks in advance!! 
-Derek

Safety checks first.  Brake pads, fluid level, all the signals, brake light and head light.  To bleed the brake by hand....fill your reservoir, loosen the bleed nipple, pump the brake and hold while tightening the bleed nipple.  Release the brake lever and test the brake.  If still soft then loosen the bleed nipple again.  Repeat as often as necessary.  

Other things to change....oil and filter, air filter and grease the swingarm.  

Other things to check....chain wear, sprockets, tires, sparkplugs.

The best carb kits are made by Keyster, in Japan.  You can get them through Z1 Enterprises, or directly from Keyster.

Oh...let's see some photos of your bike!

HRM nailed it, especially make sure it will stop before you make it go!

I've restored/rebuilt a fair number of those Keihin CV34's and understand them pretty well.  Regarding carb kits, I'm unaware of any decent kits.  The commonly available kits contain little more than a few random O-rings, but not all that are needed to do a rebuild, and a float needle.  Oh, and they typically include a pilot screw which you shouldn't even need.  Of the available kits/parts, Keyster makes the best float needles, other than OEM Keihin (which are expensive.)  I buy O-rings in bulk, and stock up on Keyster needles.  If jets are needed, hit up Z1.  They stock most all the required jets.  

Regarding O-rings, these are the sizes needed to rebuild the carbs.  I've got spares, but I'm not sure if I've got enough to hand out.

Pilot Screw: 1.2 x 2.6
Pilot Plug: 1.5 x 2.8
Fuel Tee, Transfer Tubes: 2.0 x 5.5
Drain Screws: 1.4 x 4.0
Float Bowl: 2.0 x 67

Regarding a new/old bike, and what to work on...

In addition to what was mentioned already, I always do the following...

Full carb rebuild.  I'm not talking about opening the float bowls and spraying junk inside and installing aftermarket "carb kits."  I'm talking about a FULL tear down, soaking the bodies and jets in carb dip, then reassembly with new O-rings and float needles (for Keihin's.)

I also perform a full brake system tear down.  This includes removing the caliper pistons and replacing the seals.  Replace the brake lines.  And rebuild the master, after making sure the master bore isn't all pitted from corrosion.

Valve adjustment.  This is critical because a LOT of hack previous owners neglect this maintenance and the valves and head can be damaged.

Thank you everyone for your time, and replies. Here's what I know for certain all lights work correctly, horn, back brake, clutch, and throttle all function properly as well. As I expected from a bike that has been sitting it needed new battery, new oil and filter, different gas, and new float bowl gaskets. I was lucky enough to find a replacement spring for my OEM master cylinder. The reservoir was really bad on it, is that salvageable? Right caliper piston is stuck and engaged, pads are fine. Left caliper appears to be in much better condition. I noticed it was leaking gas and checked the petcock, almost the entire gasket was shredded. Lucky I didn't blow up. What are the orange plugs that resemble thumbtacks in the float bowl next to the main and secondary jets? This is my first time OWNING a motorcycle. Have ridden since I was 6 years old. Never had the opportunity to work on them until not. Any tips or guidance is much appreciated. Thank you all!!

I've never heard of carb dip. What type of container would I use to soak them in? I have replaced my float needles and I ribs all around. Would you recommend I rebuild the old caliper piston I have, but a used one, or order complete new front brake system? If the latter where can I order it from? I've no idea how to adjust the valves... Explanations, recommendations, general tips and advice are much appreciated. 

Hi Slade 
PLEASE   click the insert all tab to complete your picture install so they will be full size . 
I fixed them for you this time
 Nice Project 
Dave 
Mod team 

wrote:

I've never heard of carb dip. What type of container would I use to soak them in? I have replaced my float needles and I ribs all around. Would you recommend I rebuild the old caliper piston I have, but a used one, or order complete new front brake system? If the latter where can I order it from? I've no idea how to adjust the valves... Explanations, recommendations, general tips and advice are much appreciated. 
 

"Carb dip" is a generic term for something like this:



The container is pretty large - looks like a one-gallon paint can - and the basket lets you soak small parts without having to fish them out of the can when they're done. You should be able to find this at most auto parts stores.

And before you do anything else, get a good shop manual for your bike. Kawasaki would be ideal, but Clymer is better than nothing. You can also look here for info: kzrider.com/filebase/category/17-kz750

Valve adjustment info and MORE, contained in the factory Kawasaki manual for your bike.  Get a free digital download here on KZR, in the Articles area here.