Two hoses from fuel tap

Hello new to forum new to restoration
There are two hoses coming from my fuel tap on KZ440 one goes to bottom of carbs(main fuel hose)
Then another that just goes to one of the carbs on the other carb there is a rubber blank
What is it?
Cheers

If your fuel tap has prime, on and off on it it will be the vacuum pipe to open the fuel tap when in the on position.
Prime is like a open tap. On is like a open tap when the engine is creating a vacuum and off is errr......... off!

Vacuum line to open the petcock while running.
Steve

Each carburetor has a vacuum port for synchronizing the carburetors.
During normal operation, one vac port is capped or plugged while the other is used to operate a vacuum petcock.

When the engine is running, engine vacuum actuates a petcock diaphragm to allow fuel to flow by gravity. When the engine is stopped, a spring returns the diaphragm to the closed position stopping the flow of fuel >> the diaphragm assy has a plunger with o-ring that plugs a petcock orifice.

ON is the normal petcock position. RES (reserve) functions the same as ON, but the fuel pickup is lower, so only use RES when the fuel level in the tank is low & refuel asap, within about 15-20 miles or you'll end up pushing the motorcycle.

PRI (prime) bypasses the diaphragm assy, allowing fuel to flow by gravity >> engine running or engine off.
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Thanks my fuel tap has prime on and reserve
I have took the tank off does that mean fuel should not come through with it on or on reserve
At moment it just runs out

With the engine stopped or tank off the motorcycle:
Fuel flow should stop with the petcock set to ON or RES. If it's leaking, then the petcock probably needs to be rebuilt.
I would disassemble it & inspect the parts, then proceed accordingly.
Edit: the problem could be as simple as an old hard diaphragm plunger o-ring or crud.

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Yup, your petcock is botched.

Rebuilding petcock's sucussfully is a hit or miss proposition. Many times it's a fail, particularly so if you cheap out and buy aftermarket parts. Buying a new petcock is safer money but some of the OEM petcocks seem to be discontinued so you need to figure out what sort of substitute will fit.

OEM rebuild parts may be available from the Kawasaki dealer & a Kaw diaphragm assy is usually pretty cheap.
If your petcock is shot with pitting or bad corrosion, a new unit may be available as well.
See parts diagrams at Partzilla for your 440, whatever particular model it is.


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I just had a similar issue with my petcock. I cleaned it out, reassembled and now fuel flows through it while bike is OFF and petcock is in the ON position. I tried removing the carbs and dumped fuel everywhere.

also, does the vent tube connect to anything on the BS-CV's?

jarellano119 wrote: I just had a similar issue with my petcock. I cleaned it out, reassembled and now fuel flows through it while bike is OFF and petcock is in the ON position. I tried removing the carbs and dumped fuel everywhere.

also, does the vent tube connect to anything on the BS-CV's?

The vent hoses vent to atmosphere. On many models they hang down between the swingarm pivot and the frame crossmember in front of it.
If the petcock is vacuum operated and it flows in the ON position with the engine off, the petcock was either assembled incorrectly, or there is a serious problem inside of it.

Scottbob76 wrote: Thanks my fuel tap has prime on and reserve
I have took the tank off does that mean fuel should not come through with it on or on reserve
At moment it just runs out

Yep, the vacuum diaphragm should seal off the fuel to the hose barb with no vacuum applied.

Much like everything, it's not rocket surgery, but you do need have a good understanding as to how it works in order to fix. As Nessism said, parts are hit-miss, and in my case I had not choice but to use a aftermarket "kit" to get enough parts to fix mine. Also to note, my petcock does seal off the gas when I take the tank off. I also put a rubber cap on it if I have it off for an extended period.

I found with the K&L kit, I had to put a larger diameter O-Ring on the diaphragm. I also had to polish the o-ring seat on the petcock housing with a dremel tool and polishing pad to an original like shine.

Gas is hard to contain, so everything needs to seal well.