Petcock Question

[az3200]

Hello again. My 2002 Ninja will run the gas tank bone dry whether the petcock switch is set to ON, RES, or OFF. What gives?

I first noticed when I had it set to ON and ran out of gas. Set it to RES and nothing. Opened the tank and it was already completely empty.

[Motofool]

You need a new petcock or a repair kit.

On has a tube that takes fuel from a higher level inside the tank.
Reserve takes fuel from a lower level (almost bottom).
If Off is allowing fuel in, then the rubber disc inside your petcock is either gone or badly worn.

[n4mwd]

There is usually a little gas in the right side of the tank. With a little practice, you can usually fling it over to the left side where the petcock is. Its not much, but it might be enough to get you to the next gas station.

The main rubber washer under the knob sounds bad. It definitely sounds like its time for a rebuild.

[GeorgeRYoung]

Remove the gas line and vacuum line from the petcock, and attach a temporary vacuum line to the vacuum port.

1) In the off position, if it leaks you need both a new gasket (the rubber thingie with 4 holes) and a new diaphragm O-ring.

2) In the off position, if you suck on the temporary vacuum line and it leaks, you need a new gasket.

3) In the on position, if it leaks you need a new diaphragm O-ring.

4) In the on position with finger blocking gas line, if you suck on the temporary vacuum line and get a mouth full of gas, you need a new diaphragm. And the bike probably won't run very well either.

In my case, it was leaking in the off position without sucking on the tube, meaning both the gasket and the O-ring are hosed. Replaced the gasket and it still leaked in the on position - replaced the O-ring. All is good.