81 kz650 petcock

Hey folks this is my first post and i'm not too sure where to put it, but I saw a gas tank post so I figured i'd post my question here. I have an 81 kz650 i'm not sure what model designation it is (f1 h1). I rewired the bike using a diagram I found on kzrider and the bike turns over. Now I need to figure out my fuel situation. This one came with a vacuum advance petcock I think and the PO said it needed to be rebuilt, but I was wondering can I just run a straight feed petcock and not have to worry about vacuum lines and leaks. If so where can I purchase one locally? This is my first build and i've never had any experience with motorcycles. Your help is appreciated thank you.

Welcome.

The petcock has a prime position and you can run the bike on this position. Just make sure the vacum line that goes to the carb boot has not been removed so that air goes into the boot.

There should be three lines. Two for carbs and one to operate the petcock.

There will be some 650 riders that will help you out. Roy

Yeah thats another one of my problems. The PO removed all the fuel and vacuum lines so I am kind of clueless to what goes where. Thanks for the quick replay.

The fuel line hooks to the larger inlet between the #2 and #3 carbs (right in the middle) on the fuel rail. The vacuum line from the petcock should go to a nipple on the #2 carb (from the left as you are sitting on the bike, second one in from the petcock side). This nipple is closer to the inside of the carb body on the outside of the carb. There are two nipples that look exactly like the vacuum nipple that are really close to the fuel rail on the #2 and #3 carbs also, these are atmospheric vents, not vacuum ports. These came with hoses on them that ran up toward the airbox stock, I've always run them open to atmosphere with no ill effects. Someone here will likely post a pic with these things labeled, I forget who the member is with the pic, but it's really helpful if you have a hard time following my ramblings!!

If your bike is a CSR, then it would be the H1 model.
When using a manual fuel valve, fuel has a tendency to leak past the float needle valves when the bike is off, so you'll have to be diligent in setting it to the OFF postion. I prefer the vacuum petcock. K&L rebuild kits should be available at Z1Enterprises.com.
(K&L parts are made in Japan & oem quality - my experience anyway).
I believe Z1 sells a Pingel/DragSpecialties fuel valve; you'll need the 34mm adapter plate. The fuel tank orifice will need to be reamed out a tad to accept the fuel screen.
Caution: sparks could cause an explosion. The vacuum port is the forward nipple on the #2 carb. The rearward port is a vent & the #4 carb has a vent port in the same location.

PS: I have a new Pingel/DragSpecialties fuel valve & the adapter plate (also new) for the 81 CSR that I will not be using. I'm looking to sell both items. Send a pm if interested. Thanks.

Here is a picture of the carbs, the PO said he rebuilt them, but didn't run it.


Here is a some pics of the petcock, it appears to be missing a fitting.

i46.tinypic.com/289dc1d.jpg



Here is a picture of the gas tank. Is this usable or will it need to be treated?

i45.tinypic.com/2nt8rjn.jpg

Some of the pictures worked some didn't, oh well.

Did he mention anything about rejetting the carburetors for the pod filters? Whatever he said...
Don't believe anything the previous owner told you.
That fuel valve is not stock for the 81 650-CSR.

Yeah, he said he had rebuilt and rejetted the carbs when he had it apart and that was the petcock that came off the gas tank.

He said once he did the carbs and had it running he saw the harness and how burnt out it was and decided to rewire the whole bike. He ended up finishing up the rewiring, but it was just a twist and electrical tape type rewire so I tore it all out and did my own with solder.

Since the bike has pod filters, it should be a simple matter to remove the carbs & have a look inside.

Remove the float bowls. You should be able to read a number that's on the main jets. Stock is 92.5 (81 650-CSR). I don't know what size is needed for the pods.

If the bike has an aftermarket (4-into-1) exhaust system, the jets should be sized for that as well.

I'm assuming a brass fitting is supposed to go there for the fuel line and the one on the back is a vacuum line. Where would I be able to get a brass fitting for that? Home Depot maybe? I'd like to get this one to work as I just want to see if the old girl will fire up.