Petcock Problem

Hello,
I have a problem with my petcock. It is gravity fed and doesn't work right. The only way gas flows is by putting it to the On setting so it flows constantly then I have to remember to shut it off when I stop. I would like to know if I can fix this by buying a petcock repair kit or should I just by a whole new one. Also anybody know which petcock I should order from Z1 for the 82 kz550 A3?
Thanks

If it has an off position it IS operating correctly. If it has a PRI (prime) setting it is a vacuum petcock and will ALWAYS pass gas in the PRI position but should only (pass gas) when the engine is running and in the RUN position.

Yes but this one will not pass gas in the run position when the engine is running. Eventually the bike dies because it doesn't get gas. The only way I can run it is in the prime position but gas constantly flows. It shouldn't work like this right?

PRI position does not require vacuum to allow fuel flow.

Other petcock positions do require vacuum to allow fuel flow.

Is vacuum tube from carb attached to petcock?

Good Luck!

Yes there is a vacuum line and I was aware that it didn't require vacuum in the pime position. That is why I set it to prime so it will run. Otherwise gas doesn't flow in the on position, even when its running, like it should. Could that be lack of vacuum coming from the vacuum hose or a jacked up petcock?

Would first assure vacuum being supplied to petcock.

If petcock fails to allow fuel flow in positions other than PRI, would then consider the petcock repair kit from Z1E.

Good Luck!

You should be able to draw enough on that vac hose to make the fuel run. It really does not take much. Just to confirm you have a petcock problem. If you don't want to do it get Paris....she checks all my batteries.

If she's still no good a re-build kit from Z1 should put it straight. BTW where is the vac tube getting its draw from? We picked up a parts bike from a JunKyard and it seemed like every hose on the bike was filled with a mud wasp plug.

I had one of the vacuum petcocks on my 79 kz650 and it just failed on me one day. I installed the rebuild kit with no help at all. Then, I got a 77-78 gravity petcock off ebay on which the handle broke nearly immediately. I am now running it with a manual on-off gas valve I got for 9 bucks.
Your problems are either A) The o-ring in the end of the gas plug has attached itself inside the hole which it supposed to plug and will not move. b) You have the vacuum line to the petcock attached to the wrong outlet of your carbs. C) Your vacuum diaphragm has torn and therefore will not move the plunger when vacuum is applied D) Vacuum line is obstructed somehow.
All these problems can be solved by A) Doing the right thing and buying a Pingel petcock and adapter plate b) Doing what I did- install a simple on-off gas valve in your gas line and turn your petcock to prime. It works, but is slightly ghetto.

Hope this helps.

mseems wrote:

The only way gas flows is by putting it to the On setting so it flows constantly then I have to remember to shut it off when I stop.

That's exactly how mine works.:laugh: