TOPIC:

GasMoney wrote: ... '82 KZ440 ltd, the engine dies within seconds of having the petcock on the ON position. Second, it runs just fine on RESERVE position. I'm noticing there's only one line coming from the petcock. (Isn't there supposed to be two lines?)....

Petcock having OFF-ON-RES positions indicates a manual petcock -- not a vacuum petcock.
There's no vacuum hose to a manual petcock.

The ON position is supposed to receive fuel via the petcock's intake tube that protrudes up inside the tank.
Perhaps crud is obstructing fuel from being able to enter the petcock's intake tube.
In RESERVE position, fuel need not flow through the protruding tube.
Remedy is to remove and clean the petcock, especially the pickup tube and associated screen.
And to remove and flush the tank in order to prevent recurring obstruction.

One fuel line supplies both carb bowls (guessing a tee connects the bowls).

Good Fortune!

Patton wrote: Petcock having an ON position indicates a manual petcock -- not a vacuum petcock.

The vacuum-operated petcock on my KZ400 has reserve (RES), on (ON), and prime (PRI).

It would be a good idea to clean it. Rust can clog the fine strainers and the vacuum diaphragm can leak.
Steve

Nerdy wrote:

Patton wrote: Petcock having an ON position indicates a manual petcock -- not a vacuum petcock.

The vacuum-operated petcock on my KZ400 has reserve (RES), on (ON), and prime (PRI).

Thanks, Nerdy!
You are correct. A vacuum petcock doesn't have a position marked OFF.
I meant to say OFF instead of ON and have edited my post accordingly.
The picture of GasMoney's petcock shows RES-OFF-ON.

Good Fortune!

Patton wrote:

Nerdy wrote:

Patton wrote: Petcock having an ON position indicates a manual petcock -- not a vacuum petcock.

The vacuum-operated petcock on my KZ400 has reserve (RES), on (ON), and prime (PRI).

Thanks, Nerdy!
You are correct. A vacuum petcock doesn't have a position marked OFF.
I meant to say OFF instead of ON and have edited my post accordingly.
The picture of GasMoney's petcock shows RES-OFF-ON.

Good Fortune!

I wouldn't say that all vacuum petcocks are like that...I am pretty sure I've seen a few vacuum petcocks with an off position before.

I don't have any on my bikes (I prefer manual ones), but I remember that while my CSR still had the original petcock, it had "ON - RES - PRIME", but some of my Hondas and Yamahas had an "OFF" and no "PRIME", though.


Looking at the posted picture, it looks like the OP has a manual fuel valve, so I guess that makes part of my reply not applicable...

Am unfamiliar with any Kawasaki vacuum petcock that has a position marked as OFF.

Good Fortune!

GasMoney wrote: . . .

Attachment 20160827_102839.jpg not found

. . . .

The above photo appears to be of a manual petcock.

Am thinking (but not positive) that GasMoney's 1982 KZ440 ltd came stock with a vacuum petcock.
However, it's not unusual to see where a vacuum petcock has been replaced with a manual petcock.

Good Fortune!

Patton wrote:

GasMoney wrote: . . .

Attachment 20160827_102839.jpg not found

. . . .

The above photo appears to be of a manual petcock.

Am thinking (but not positive) that GasMoney's 1982 KZ440 ltd came stock with a vacuum petcock.
However, it's not unusual to see where a vacuum petcock has been replaced with a manual petcock.

Good Fortune!

Yes, I agree....I think the EPA made vacuum petcocks mandatory on large displacement street bikes by then. Honda's CBX and most CB's went from manual to vacuum in '80-'81.

My main beef with the Kawasaki vacuum petcock (on my '81 KZ1000CSR) was that when the vacuum valve failed, you couldn't shut the gas off to remove the tank. I either had to syphon the tank or let gas spill all over while trying to pull the tank off the bike.

On my vacuum equipped Hondas, I would have to crank the engine way too long before fuel would fill the carbs, and I was burning up motor brushes and solenoids.

All my carb bikes have manual fuel valves now....

Still, the OP's engine's poor running sounds like there are intake vacuum leaks and other carburetor issues....

Kray-Z wrote: ... It is a vacuum operated petcock and you are missing the vacuum hose connection. This design only allows fuel to flow in the "on" position if the engine is cranking or running, creating intake vacuum. If it is missing the vacuum hose connection, then it would only run on reserve like you say, as reserve is also the "prime" position that bypasses the vacuum valve for easier starting when it has been sitting for a long time. You will need the Kawasaki Service Manual for this.

Thanks. I think I'll replace the petcock for the correct one with the vacuum hose connection. Hopefully that will clear up the other problems.

Kray-Z wrote: That shop likely had to clean out the carbs the second time because of the crud in the tank, not because they didn't clean the carbs well enough the first time. You can't blame them if more dirt got washed into the carbs from the tank after they cleaned them the first time. They should have checked the tank, though, and installed an in-line fuel filter (this is a must have), but it isn't their fault your tank had crud in it. As it stands, now you don't like them and they don't like you - maybe find another shop and start over instead of going back for more abuse...

The tank was spotless. The radiator shop did an amazing job there. The petcock may have been the wrong one but it was brand new as was the fuel line (and in line fuel filter). So for them to replace the fuel line was just nonsense. If there was any rust in the tank it was from one of their dental fillings when they spit in it. Most likely they didn't do a great job the first time in hopes that I'd hand them more money each month. The float needles, vacuum diaphragm and everything was brand new, all they needed to do was sync it up. I didn't even list the other issues I chewed them out on because it didn't pertain to this post. I could have heated a pot of coffee with the energy expended getting all my money back.

This is a project bike so anything I'm doing here is just for fun. Finding that air box is next to impossible, been looking for over a year. Pods is what I have on hand so that'll do for the moment. Better than duct tape right? I hear ya, and thanks for the precious info.

Hey, having the manual petcock isn't a bad thing....I prefer them over the vacuum type myself. Given your latest info, and now realizing that you had the tank cleaned before the crabs were cleaned, new petcock, fuel line, in - line filter, etc. ,then I am now thinking a few other possibilities:

Take the petcock off and check the inlet tube for blockage of the screen (this was mentioned in a previous post by Ed, I think), and also check that the petcock is assembled correctly. On the old manual petcocks, it is possible to disable the "ON" position by installing the valve 180 degrees out of position (only the "RES" will flow fuel). Next, check the right hand carb's vacuum port and make sure it is plugged like the left carb (I see the plug on the left carb in your photos, so I know that one is o.k.).

If that checks out, then check your intake rubber manifolds (the parts that hold the carbs on the engine) for cracks or any other signs of deterioration, as this is a common source of vacuum leaks on old bikes. Also check the condition of the band clamps that clamp the carbs to the rubber manifolds. They have to be tightened enough to seal but if they are over tightened, they become damaged and will cause a leak. If you see bending or distortion of the metal at or near where the clamp screws are, replace the clamps and be careful when tightening these - they don't have to be very tight to seal if they are in good shape.....

Post a pic or link to the filters you plan on using....and some pics of what is left of the air box and runners on the bike, and the diameter of the tube / part you want to fasten the filters onto....next time I get back to my shop, I'll look up the K&N filters that should fit...

For now, try turning your pilot mixture screws out 2 turns....but make sure you record how many turns out they are now first.

I'm a big fan of my bike's manual petcock. There's not much that can go wrong since it has no diaphragm and such that can tear or leak. Turning it off when I park the bike is no more difficult to remember than turning off the ignition. Ed

Kray-Z wrote: ... My main beef with the Kawasaki vacuum petcock (on my '81 KZ1000CSR) was that when the vacuum valve failed, you couldn't shut the gas off to remove the tank. I either had to syphon the tank or let gas spill all over while trying to pull the tank off the bike....

Have on occasion used vise-grips clamped onto the fuel line.

Good Fortune!