need help, petcocks

[railroad]

I had the carbs on my xs11g (1980) and what a difference it made. How ever, two days later when I shut off the engine gas starts leaking out of the air cleaner box. And it is very hard to start (flooded). When I pulled the gas tank the left petcock is leaking, I pull it apart and clean and reassemble it and it doesn't leak untill the second time I run it. I buy the rebuild kit and it runs fine untill I run it then it leaks again I pull the tank off and take it apart again alongh with the other one to check if I put it together wrong put them back on let the tank sit over night, no leaks run it in the morning for five minutes,no leaks, take it out on the road and in about ten minutes it starts running rich (missing under throttle) and leaks when I park it. It's probably something real simple but I can't figure out what. any one have any ideas?? I would rather keep it stock rather than go to a on off reserve petcock as when I had my Norton I could never seem to remember to turn it off.

[JWSanders]

Go down to the bottom of the forum list and you will see maintenence and repair sections. Each has a section for carbs.
Tell it to look for posts from the beginning if you dont see any posts in those sections. There's a wealth of info there!

Theres a really good post in the repairs section about petcocks: http://www.xs11.com/forum/showthread...=&threadid=142

Sounds like the carb floats may be sticking on you too, or their height is off. Might want to look into that, also.


Good luck!

[Ken Talbot]

If you have a fuel leak, you have both a leaky petcock and a leaky float valve. If either one works reliably, there cannot be a fuel leak.

Let's start with the petcock problem as there's lots of existing threads on float valves. In this photo of a dis-assembled petcock, look at the part on the bottom left:


You will see a round brass piece that feeds through a small orifice to the vacuum nipple. When vacuum is applied, it pulls the diaphragm to one side and allows fuel to flow. Without vacuum, the spring behind the diaphragm pushes it the other way and shuts off the fuel flow.

The problem comes from the wee orifice inside that brass piece. Often, when the vacuum is released, this orifice plugs itself shut and keeps the diaphragm from moving back. You can see this effect if you try to blow through the vacuum nipple. Yes, we're talking spooge again, just like in the master cylinders. Take a piece of wire and ream out this orifice so you can blow through it without any resistance. Then you'll know that when the vacuum dies, the spring can do its work and push the diaphragm to close off the fuel flow.

[COOL TOM]

Is the gasket still available for a standard and an XJ?
Got standard from po who took off petcocks and lost gasket.
Am going to paint XJ and XS tanks and want to put on new gaskets.

Thanks Tom
82XJ DAILY RIDE
78XS FIXING UP
79XS PARTS BIKE

[railroad]

thanks

Thanks so much Ken, your tip on cleaning out the hole did the trick. No more leaking. I used a wire to break the spooge loose then used a can of wd40 with the spray hose to blow it out of the tube. It still runs like crap after about 5 miles so next week I'll get on the floats. Anyway, thanks again.

[corey]

Sorry to dig up an old thread....

So do the Special models not have a spooge hole at all? Due to the vast differences in petcock styles, I would guess not...

[Ken Talbot]

That is correct, Cory. On a Special, the spooge hole is in the octopus. It looks the same and acts the same, and is really as easy to clean. Lots of people give up on their octopus and go back to having to turn their petcocks on and off all the time, but they can be fixed.