TOPIC:

It doesn't take very much. When you're ready we'll guide you through.
Steve

What year is it?
Start with simple things
I would rebuild the petcock and get rid of the inline filter and shut off first.
If your bike only runs on prime then you don't need the extra shut off, just turn it to on, and I may get some flack for saying this but if the filter in the petcock is clean and has no holes then you don't need an inline filter.
Some inline filters(not all) can clog up because they are too fine. any crud that goes through your system only needs to be smaller then your jets to get burned up.
If you rebuild the petcock correctly and run the vacuum hose to the right port the automatic shut off will work again.

It's a 1980.

The vacuum hose on the petcock (no joke) has a golf tee stuffed in it. Theres a bunch of hoses from the carbs going to nowhere, so I'm gonna have to look up a schematic and figure out what is going on.

Does gas come out if you remove the TEE? All nipples on the carb holders need to be capped.
Steve

I'm not sure. I have the gas tank off the bike, and the petcock and fuel sensor removed. I'm currently cursing myself for dumping pennies in the tank, since I'm having trouble removing them.

Also, does anyone know where I can get part 11039-003? Its part #8 here: www.kawasaki.com/Parts/PartsDiagram/144005/1978/KZ650-B2
Do I actually need it? Could I make one? Could I use something else?

No eBay APP ID and/or Cert ID defined in Kunena configurationYou should put your bike info in your profile , it makes it easier to help
Do you have a Kawasaki shop manual?
if not here is the link to a 81, I don't know if it is the same as the 80 but it should be close
kzrider.com/modules/ServiceManuals/Kawas...l%20KZ650%201981.pdf

Page 3-2 shows the inside of the petcock, over time the wonderful ethanol added fuel we get these days will destroy the original O-rings also over time lacquer from old gas builds up if the bike sits.

don't worry about getting a syringe or vacuum gauge there are easier ways to check the system

Well, I seem to have cleared up the fuel shortage issue, now fuel leaks from an air filter when I leave it on Prime. Ill have new seals for my petcock in probably tomorrow. I also got some vacuum line to actually connect the petcock, which should be pretty easy once I find where It connects in the shop manual. I might try and buy a physical copy, since that thing is a royal pain to flip through in pdf form.

EDIT:

I set up the petcock and got it all working, it still does leak gas from the air filter though if I leave it idle too long, but I went on a nice long ride and I did not bog down. I'm still going to look at the valves though just to be safe, and I should probably clean the carbs, since this overflow would indicate the carbs have something not quite right.

The previous owner did another weird thing: The hoses at the bottom of the carbs all go into a little can he has ziptied to the frame under the right side cover. Where should these hoses actually go to?

I figured out why the original owner had installed pod filters: He cut the battery cage, riveted some bent drawer glides onto it and stuffed a bigger battery in it. This then left not enough room for the airbox. I drilled out his rivets and I'm buying a smaller battery I can fit in the cage once I fix it. I am going with a smaller one, since the original dimension ones are all lead acid with the acid vent hoses and I don't really want that. Being as I have a kickstarter, I only really need something there to complete the circuit and power the lights while I start it.

I've been refurbishing my airbox boots with a soak in a 1:1 mix of 91% isopropyl alcohol and Methyl salicylate.

I need a nice warm day to remove the carbs to install the airbox now.

It would be a good time to spray out your carbs and get new o-rings and float bowl gaskets.

Are those VM carbs? if so this guy sell a high quality VM o- ring set for around 23 bucks delivered. www.cycleorings.com/VMkit.html
I know it says Suzuki but they used the same Mikuni carbs.
They fit right in my VM's and I have extra sizes left over , around 40,000 miles on them with no trouble
You would still need to get float bowl gaskets elsewhere
But first make sure you have the VM24 carbs like 79 has.

Patton posted very helpful diagrams on how the flush the passages but I can't find them yet

So I have taken the carbs off (and installed the airbox, which was a pain) and opened the bowl of the carb that was leaking gas from the pod filter. I then opened the bowl that was to the right of it, which would be up hill to it if it was sitting on the kickstand. The floats were not stuck, but I did find something.

These two little pieces were in the bowl of the rightmost carb. I found where they go, but I am missing this little retention clip thing (picture 3 shown).

What is this tiny piece, and could it being missing from carb #4 cause gas to leak from the air filter of carb #3?

Thanks for the help, I do appreciate it.

Those are part of the accelerator pump. See numbers 18 and 19 in the parts diagram.

www.partzilla.com/catalog/kawasaki/motor...erator-pump-kz650-b3

That float bowl looks pretty dirty. That is just the sort of stuff that can prevent the float valve from sealing and create the overflowing problem you have.

Looks like you lost a tiny Little circlip. Never seen this vent or valve mechanism in a carb bowl.
BTW you have a lot of rust particals in your carb bowls, check your fuel tank.