Is my fuel shut-off working?

[Biker Bill]

 ???I turned my fuel shut-off to the "OFF" position and let the engine run to use up the fuel in the carbs before storage (rather than leave the ethanol fuel in there to do mischief).
  The engine kept running and running.  It finally stopped but I was able to restart it again.  On another bike I own (Harley) I can hardly make it out of the driveway before that quits with the fuel shut off in the "OFF" position.
  Is my Valk fuel shut off defective??? or is this normal on the Valk? 

[Wil]

My petcock was defective when the bike was barely a year old.  I chunked it and installed a manual Pingel.  I was always afraid I would lose vacuum on the road with the OEM and be stranded.

Wil

[salty1]

I would say your petcock is not up to speed, probably needs to be rebuilt.   ???

[fudgie]

Well how long did ya leave it run? I think mine would got 2 miles before dieing.

[signart]

With fuel in the bowls of 6 carbs, that thing will run a long time sitting on the stand.

[Mr.BubblesVRCCDS0008]

Turn the fuel off and take down the road. You should run out of fuel within two or three minutes depending on how fast your going.

[donaldcc]

  if bike is parked and you shut off petcock you might as well have lunch and come back.  try it on the freeway at 75 mph.  mine still is 2 -3 miles at speed. 

  don't check it in garage, not a good test, but if you do, and have lunch, when you get back it SHOULD have shut down.

[Gryphon Rider]

I would say your petcock is not up to speed, probably needs to be rebuilt.   ???

Based on what?  A Valk will happily idle 10-15 minutes after the fuel valve is shut off before dying.  BTW, the "off" function cannot be rebuilt with any kit, but requires the valve to be replaced.

[salty1]

Gryphon wouldn't a weak spring or small tear in the diaphragm allow for the symptoms described by Biker Bill?     ???

[Ricky-D]

There is only one way to inspect the petcock for accuracy of the "off" function and that would be to disconnect the fuel line at the petcock and view the results.

The should be no dripping at all.

Expecting the motor to run out of gas (at idle) when there are six carburetor float bowls full of gasoline is unrealistic and not based in any kind of reality.

***

[Chrisj CMA]

There is another problem some arent aware of.  The fuel valve (the part you turn) has detents and a little ball bearing and a spring.  Is easy on an older valve to turn it off but not have the ball "snap" into its detent.  If its almost on off but the ball is hung up and not clicked in good, well then you are really on reserve.  All the ports are open at that point.

[custom1]

Gryphon wouldn't a weak spring or small tear in the diaphragm allow for the symptoms described by Biker Bill?     ???

Depends on which symptoms you are referring to.

Taking a long time to shut down at idle would be normal. Lots of fuel in the bowls. I can go a few miles after turning the petcock off. Just turning the petcock off has nothing to do with the diaphragm, because the engine is still running and making vacuum to hold the spring back. That part of the petcock only closes after the engine is shut down. It is only there as a safety if the ball doesn't seat in the off position while the bike is parked. Some people never shut the petcock off and rely solely on the safety half of the petcock to shut the fuel off when parked. That's not how it was intended to be used. If you turn off the petcock, you would have the have the ball leaking (or forget to shut the petcock off) and the diaphragm leaking to get a hydro lock.

Now if your talking about being able to restart it, then that might indicate a problem with the diaphragm. After restart how long did it run?

Like RD said, the best way to test it is look at the flow. Test the ball in the off position with vacuum to the diaphragm. Should be no flow. Test in off position with no vacuum. Should be no flow. Test with ball in on position with no vacuum. Should be no flow.  Should only flow fuel in the on position with vacuum applied.

[Biker Bill]

Okay! Lots of info. Thanks guys!
 To answer CUSTOM 1:   After restarting it ran about 5 minutes and shut down.  I then restarted it again and it ran a short while and quit.  I did not try again.
  Since it is going to be stored 9 months I thought it would be good to clear the carbs. I di have StarTron in the fuel to help counteract the effects of ethanol and to stabilize the fuel. 

[Kylenav]

This brings up a new question for me.  Why does everyone insist on turning of the fuel to prevent the dreaded hydrolock.  If it takes 2-3 min at speed to drain the bowls then that tells me the bowls hold more than enough fuel to cause a hydrolock.  Am I missing something?

[Ricky-D]

The fuel remaining in the float bowl after shutdown remains in the float bowl.

There is no reason to think that fuel will somehow flow into the motor.

***

[gordonv]

The fuel in the bowl, will stay in the bowl, even if the needle is stuck open. The thought is (and some say it has happened) that there is enough fuel in the fuel line after the petcock, to flood the cylinder and cause a hydro lock, IF the float bowl valve is stuck open.

When I had my Valk IS, I almost never turned off the petcock. But I did test it every week. Remember you need 2 things to happen before you can have hydro lock.

[custom1]

If you turn the valve off you need three things to happen.   

People also talk about the vacuum line to the #6 cab as a path. You would need both diaphragms in the petcock to be bad for that to happen. So again if you turn the valve off you still need three things to be bad to get the hydro.

[Brian]

I had my tank off the frame and sitting across two saw horses when I noticed the gas never stopped dripping in the off or on position with no vacuum. I didn't mess with it at that point and just replaced it with the manual pingel.