OEM petcock

[Roidfingers]

I have a fuel rail leaking between 3 and 5 carbs. While going outside several times to wet them again with gas. I noticed this......

With bike not running, so no vacuum to petcock, with switch in off position, I would get no leak. So thinking no gas to rail. With switch turn to on or to reserve, I would get gas and the leak. So I thought maybe it was still holding a vacuum. So I then unhooked the vacuum line from #6 intake that goes to petcock and I still had the same results.

This is not functioning right. Correct ? Or is it?....   

[Hook#3287]

No, you should have no fuel running at all, w/o a vacuum.  Something must be holding the diaphragm open.

You could try unplugging the hose from the petcock, if you haven't already, maybe the hose is pinched.

[Roidfingers]

I rebuilt the petcock not to long ago. Could I have not rebuilt it properly for this to happen? Seemed to be running rich since then too???? Could this be the cause?

[Gryphon Rider]

A problem with the fuel diaphragm would cause fuel to flow with the valve positioned on ON or reserve.  I don't think this would cause a rich condition while running.

[Dusty]

The little hole in the picture (7 o'clock position ) has become plugged up with debris  ( dust or dirt or ?). This causes the diaphragm to stay open because the vacuum will not bleed off. The selector ball is working to shut off your fuel . Try to take your vacuum line off the petcock and shoot some carb cleaner or WD-40 into the vacuum nipple to flush out the debris . Use compressed air if you have it to try to dislodge the debris . It may not flush the crap out because the vacuum in the petcock is holding it in place. If it does not flush out thru the nipple you will need to disassemble the petcock to release the vacuum . 

Dusty

[Roidfingers]

Well, it's nothing to remove the tank now. So gonna pull it. Check what you said. Also open up to confirm correct assembly when I rebuilt it. I'm pretty maticulus when working on things, but I am human. After I complete some work. Carb rebuild etc... I always question did I see and do everything right. Thanks all for input. Gonna go off this rebuild, but a little faster. lol.

https://www.youtube.com/watch?v=RHTt_dhJskc

Also, I purchased the 3 new fuel lines that go from tank to fuel rails. Has anyone changed these before and did they trim them at all? I have tried to get down hill all the way but seems just not right. Whats the correct routing and length of each line. Left from T, right from T and tank to T.

[hubcapsc]

I put a lot of stock in the test at the end of this shop talk article:


http://www.valkyrieriders.com/shoptalk/petcock.htm



Now that it is all back together. Its time to test it to ensure it works properly and won’t require pulling the tank back off later. Simply attach a (Clean) rubber hose onto the vacuum nipple. Apply a slight vacuum to the hose while looking down the fuel outlet. Yes, your mouth works great for this! Just don’t suck very hard. It’s very easy to overcome the spring tension. As you apply vacuum/suction you’ll see the diaphragm pull away from the main section. When you release vacuum/suction the diaphragm will SLOWLY return sealing off the flow of fuel. If it does not either you assembled incorrectly or your check valve is still clogged or defective. If all works, you’re done!

-Mike

[Blackduck]

Have had the bleed hole block and hold the petcock open. Used a very fine letter drill bit to clean it then compressed air.
Another view from the inside
Cheers Steve