CAn anyone show me where the Vaccum line for the petcock goes i belive thats why im having a bad idle cause there is no line hooked up to the back of the petcock so i dont know where it hooks up to get pressure. Any help would be great oh yeah its a 81 xs400 If that matters.

CAn anyone show me where the Vaccum line for the petcock goes i belive thats why im having a bad idle cause there is no line hooked up to the back of the petcock so i dont know where it hooks up to get pressure. Any help would be great oh yeah its a 81 xs400 If that matters.

the fuel line will be closer to the front of the petcock, or the thing you turn to engage different fuel options. And the vaccum line is behind it, youll have to lift up the gas tank to see it, because its at the very back of the petcock. Also poor idle could mean clogged idle jets, I just put new ones in mine, which you might want to consider, they are like 4$.

the fuel line will be closer to the front of the petcock, or the thing you turn to engage different fuel options. And the vaccum line is behind it, youll have to lift up the gas tank to see it, because its at the very back of the petcock. Also poor idle could mean clogged idle jets, I just put new ones in mine, which you might want to consider, they are like 4$.

Yeah i know where the vaccum line thing is on the petcock but where does it hook up to?

Yeah i know where the vaccum line thing is on the petcock but where does it hook up to?

OHHHH it hooks up to the top of one of the intake manifolds, there should be a brass fitting for a tube like on the back of the petcock sticking stright up on top of one of them, in fact both of my mainfolds have one, we just sealed one so you might have to take the rubber piece off if they are sealed.

Thanks alot sir.

you also use the vacuum on the the manifolds to hook up the vacuum gauges