So My House smells like gas

[zore]

My best guess is the fuel petcock took a pooper on me.  I drain the bowl and it refills and then spews out the overflow (I thought the drain screw was not sealing)  I bought one of these but want to make sure I'm not missing anything.

http://www.ebay.com/itm/Fuel-Petcock-Valve-Shut-Repair-Rebuild-Kit-XZ550-RJ-RK-VISION-82-83-/200919113629?pt=Motorcycles_Parts_Accessories&hash=item2ec7b65f9d&vxp=mtr

[The Prophet of Doom]

If it is doing that your carb valves need repair (or your floats aren't floating). The float should rise, press the valve and shut off the fuel flow to the float bowl

You petcock may also need repair.  It should only flow with vacuum unless it is set to PRIME

[Jimustanguitar]

I replaced my petcock internals last year, but still couldn't get the darn thing to completely shut off. I've come to the conclusion that a few drips are acceptable on these petcocks. The float valves should keep this from being a big issue, but the floats do tend to stick once in a while. If you determine that a float is stuck, a few taps with the handle of a screwdriver should get them moving freely again.

I bought an inline shut off valve for the vision this year. We'll see how many times I have trouble starting it because of my bad memory :)

[zore]

I figured the float was a secondary issue, but the main issue to me was the fuel not shutting off to begin with.  Now thinking about it, it could have been this way for a long time but the needle and seat were keeping it from becoming an issue.  I think I have more than one new needle and seat kicking around so I'll throw that in as well.

[Rikugun]

I figured the float was a secondary issue, but the main issue to me was the fuel not shutting off to begin with.  Now thinking about it, it could have been this way for a long time but the needle and seat were keeping it from becoming an issue.  I think I have more than one new needle and seat kicking around so I'll throw that in as well.

As you found out both issues are important  - keeping the fuel from flowing when it's not supposed to and the carbs shutting off the supply when they're full.  :) Remember a poor fitting O-ring that seals the brass seat in the carb body can also fill the bowls even if the needle is closed and functioning properly.

On the backside of the diaphragm shown in your link, there is an O-ring that seals an orifice in the aluminum body of the petcock. Not shown in the pic is a small spring that pushes that "valve" closed when engine vacuum is not present. I suspect in Jim's case the O-ring is not sealing or the spring is missing or weak. A common failing is corrosion in the petcock may have rendered the seating surface for that O-ring to no longer be smooth. Also, debris in the tank small enough to get by the screen (if still intact) can collect and foul that seat as well.

[QBS]

Install an inline fuel cut off valve and be done with it.

[The Prophet of Doom]

The float valve is the more important  - even if the petcock is fine, it will still overflow when the bike is running, If the bowl is overfull it will also impact your air/fuel ratio

[QBS]

roro, has that been your experiance?

[The Prophet of Doom]

Very much so -   it had started running poorly at higher revs and I was powering through petrol - 150km to a tank.
It was only when I had it idling on the workstand that I noticed a big pool underneath.  It didn't do it when the engine was off so I hadn't noticed.

Cleaning the valves was all it took. an hour well spent.

[QBS]

Thank you.  That's good to know.

[zore]

Very much so -   it had started running poorly at higher revs and I was powering through petrol - 150km to a tank.
It was only when I had it idling on the workstand that I noticed a big pool underneath.  It didn't do it when the engine was off so I hadn't noticed.

Cleaning the valves was all it took. an hour well spent.

It's not leaking but a drop every few seconds so I'm not overly concerned.  It only pools when the bike isn't running which almost made me think it was to drain screw and not the float.  I'll have a better look at it when I pull it out of the garage.