Brand new petcock has no flow.

[Guest]

1980 GS550L

Been working on my 550 "the lemon" for a while now. Close to being done and now I'm dealing with this irritating petcock issue. BRAND NEW petcock, installed on tank and let gas sit in it overnight to make sure everything was nice and lubricated before I started turning the valve. Turned it to the "on" position the next day and not a drop of gas came out. Moved the valve back and forth and even gave it a couple soft taps thinking something might be stuck. still nothing. Took it apart and everything looks perfectly good (like it should). put it back together and gently blew and sucked on the gas supply line (big one) you could hear the membrane on the inside pop back and forth. tried to do the same thing on the vacuum line and could not get any air to go back or forth. ended up blowing really hard and sucking really hard and still nothing. Is this thing defective?

I have dealt with these aftermarket petcocks several times and have had issues with them EVERY TIME. I hate them... anyone have an original in good shape? or know whats wrong with mine?

[gustovh]

It takes vacuum to operate the valve "before" any gas will flow, though by your description, something does not sound right.

Disconnect your fuel line and stick another line on the tank, put that line in a container and disconnect the vacuum line from #2 carb and give the vacuum line a suck, gas should flow.

V

[tom203]

"Turned it to the "on" position the next day "

out of curiosity ,what position was it in when you installed it?
And when you later disassembled it, were you careful about the odd spring positioning?

[terrylee]

Maybe dumb question on my part, but was bike running when you tried it? Has to be to create vacuum.