petock question

[SilentRaven]

so i just bought a new petcock because my old one was impossible to turn, like i had to use a wrench to turn it! I just put my bike back together after a carb clean and tank repair. once i added gas back to the tank, it just started to flood out of the carbs. i tried shutting off the petcock but no matter what setting i was on it would still flow out. I thought that if it was on run or res that it would only flow out if the engine was on, and prime it would flow continuously. is there something i should check to make sure it is assembled correctly?

[Nessism]

What petcock did you purchase? With a properly functioning OEM petcock there will be no flow without vacuum pulling on the vacuum port unless the level is set to Prime.

[SilentRaven]

i got it off ebay. thats what i thought, might have to run some tests. thank you

[SilentRaven]

quick question the old petcock had the vaccuum line coming off the back at a downward angle, the new one has it at an upward angle. does this make a difference?

[Nessism]

quick question the old petcock had the vaccuum line coming off the back at a downward angle, the new one has it at an upward angle. does this make a difference?

No difference.

[LAB3]

A brand new petcock should work the way it's supposed to right out of the box. Taking it apart to find out why it's not working isn't a good idea, you should return it for a different one. If you open it up and there's signs that you DID, getting it replaced free of cost probably isn't going to happen.

As to the direction the vacuum line is pointing, I'm not sure that's an issue if it works like it should. If it where me, I'd see how the seller wants to handle getting a replacement sent out. I'd expect them to want to see the original first, that's fair for them.

[SilentRaven]

thanks guys, took the bike apart again today and found out the main gas line to the carbs was not seated properly. Also tested the old and new petcocks, new one works fine old one does not. To test them I made a mini 'gas tank' out of a old bean can and attached the petocks to the bottom of it, and then filled it with gas and checked the settings. also sucked on the vacuum line to test that as well. got everything back together and seems to be running fine, no leaks!

[salty_monk]

What petcock did you purchase? There are some Ebay OEM copies that are quite cheap. It would be good to have some evidence that one of them works...

[Gorminrider]

To test them I made a mini 'gas tank' out of a old bean can and attached the petocks to the bottom of it, and then filled it with gas and checked the settings

No test is useful unless the vacuum petcock on RUN/RESERVE can hold back against a full tank mounted on the bike.

[salty_monk]

I don't think I've ever had one that leaked with a full tank that didn't leak with a gallon or two in the tank as well... Just personal experience.

[Gorminrider]

I have. Particularly an Ebay vacuum tap. worked fine with half a tank-but let gas past it with more. The spring was too weak to offset the increased pressure.

Because,as a rule, Pressure increases with depth.

[JoeNashville]

Boy this was a timely thread!
I'm going to test my petcock on the tank with fuel before I put it back on the bike!!!