Petcock ? I've never heard answered.

[Ferris Leets]

     The stock rooster seems to have a problem with failing to stop fuel flow.  If it is shut off is it still able to leak?  Why would you add an aftermarket rooster if you still have to shut it off anyway?
     Other question.  They also can lose vacuum and fail to deliver fuel.  Is that on the reserve as well? 
     Someone had a method for basically eliminating the vacuum control and turning it into a manual on/off rooster.  Why not just do that?

[Daniel Meyer]

     The stock rooster seems to have a problem with failing to stop fuel flow.  If it is shut off is it still able to leak?  Why would you add an aftermarket rooster if you still have to shut it off anyway?
     Other question.  They also can lose vacuum and fail to deliver fuel.  Is that on the reserve as well? 
     Someone had a method for basically eliminating the vacuum control and turning it into a manual on/off rooster.  Why not just do that?

If you use it as a manual petcock...either by turning it off every time or eliminating the vacuum parts, the "valve side" will eventually wear out and eventually leak even if off or possible reserve-to-on...it's just a ball, spring, and o-rings.

If they lose vacuum, and cannot deliver fuel, that is in reserve as well. The petcock is designed to not deliver fuel in any position without vacuum.

The most common failure is the vacuum diaphram...it's an easy rebuild...if you check its function and for vacuum leak-down every 10,000 miles (when you pull the tank for air filter change), you will spot problems before they bite you. They do not fail "suddenly"...they give plenty of warning if you are checking them out.

The problem is they do not last forever and most folks ignore them until there is a probem.

You can replace it with a pingel...either vacuum or manual...but the reserve is vastly reduced and you have to reach WAY under the tank to operate the valve. There are mods for both issues...if you go to the pingel I'd recommend you do the mods so you at least have similiar functionality.

[Bone]

My 98 Tourer had the diaphragm start leaking. The gas was going down the vacuum line making #6 spark plug sooty. I ordered a kit and while waiting for the parts I continued to ride. Found the plug would start fouling at about 100 miles. Each time I would leave the garage I would look at my mileage and if near 100 miles just switch with another plug .
During this period waiting on the parts someone posted the by-pass link. That was what I really wanted. By-pass is easy I have a manual petcock now. I also have the rebuild kit if I want to go back to vacuum but I'm pleased with the manual operation.
I have been shutting off the petcock on every bike I've owned every time I shut off the engine for 40 years. Have yet to wear one out from using it, but parts do fail.

[Red Diamond]

     The stock rooster seems to have a problem with failing to stop fuel flow.  If it is shut off is it still able to leak?  Why would you add an aftermarket rooster if you still have to shut it off anyway?
     Other question.  They also can lose vacuum and fail to deliver fuel.  Is that on the reserve as well? 
     Someone had a method for basically eliminating the vacuum control and turning it into a manual on/off rooster.  Why not just do that?

When reading post on stock petcocks, you will discover a considerable amount of paranoia regarding this item. I.E. they are prone to leakage, causing hydrolock; the in tank filter is not sufficient enough to trap particles, an inline filter is needed, they must be shut off every time the bike is stopped, an electric shut off valve is needed, I could go on and on. I have at on time owned three Valkyries, still have two of them, not one problem with the stock petcock, of course I never turn them to the off position unless the tank is being removed. A friend has a 2k I/S, 130K+ miles, no problem yet. Don't turn it off every time you look at it, it will be fine.

[Patrick]

Like Dan and Bone stated, the factory valve can have some issues.. Even turning it on and off every time doesn't help unless the valve is in the exact correct position.. If the ball is off just a wee-bit it'll still pass fuel.. The main concern is fuel-lock which a fair number of folks have experienced and having this happen once in a lifetime is once too often.. Personally I think the installation of an in-line fuel filter is the best guard against the dreaded fuel-lock,but, its still not a guarantee.. If just a float valve sticks, a fuel-lock can occur but you may survive it.. But if a float valve and the fuel valve sticks at the same time and you don't realize it you may be for an expensive fix.. Most of us that have experienced a fuel-lock are not about to take anymore chances.. It doesn't bother me at all to reach for the valve handle, its just part of the normal ' pre-flight/ post-flight check list '..

[Scott from FL, now in Maine]

All the comments here seem accurate to me. The only thing I would like to add is that we hear on the board of all the troubles, but rarely do we hear of all the trouble free miles. This board is to help fix troubles and when there are none we hear nothing  Take the knowledge on board, do proper maintenance to check for troubles, and enjoy the ride!!!

[asfltdncr]

And if you do use the stock petcock, do not actually tighten the fuel selector knob.  Leave it a little loose or wobbly.  As a rule, a real tight selector will not allow the valve to manually shut off properly.

[Robert]

In the off position it will still leak fuel There is no positive off.
In the on position it will not let fuel pass.
stock petcock is a pos and why with so many complaints would anyone risk hydroloc by useing the stock petcock.
If you need more info look in archives this topic has been beat to death.

[Sodbuster]

All the comments here seem accurate to me. The only thing I would like to add is that we hear on the board of all the troubles, but rarely do we hear of all the trouble free miles. This board is to help fix troubles and when there are none we hear nothing  Take the knowledge on board, do proper maintenance to check for troubles, and enjoy the ride!!!

Scott -  thanks for the positive note !!  We always hears how bullet proof these Valks are but sometimes reading this forum you would tend to think otherwise.

I installed a manual pingel petcock and pingel inline filter. It's not a big deal to reach under the tank and is peace of mine.

[KW]

I agree with Red . . . . .  I've never turned my gas off except when removing the tank and have never had a problem.