Float valves supposed to leak???

[81xsproject]

Last year I bought a BS34 conversion kit from Wired George of wgcarbs.com for the '77 KZ1000. Recently I have got the bike running and have noticed that if the petcock is left on the carbs will drip and the crankcase will will up. I contacted WG about the issue and he says

The float valve seat and needle assembly are not intended to be a
fuel shut off... they are there to meter fuel when the bike is in
operation. They WILL leak if you leave the petcock on. The manufacturers
recognized in the late 70s that many owners failed to put their petcock
into the OFF position when parking their bike so they came up with a
vacuum actuated petcock system.

The BS 34's on my XS don't leak, what do you all think about this?

[prometheus578]

"Technically... he may be correct..."

In my experiece, he isn't.
Sure, with some style float needles, the all metal ones, it's only a precision metal float taper to metal hole seat seal, but it should still hold for a while.
I can let my metal to metal carbed bike sit for months (on prime) and have no leaks. Ok, maybe it's technically leaking to a degree, but not to the degree that the carbs flood.
What I believe you're describing, is a leak that's very apparant, like if you set the carbs on a work bench, hooked up fuel, and after coming back thirty minutes later you'd have a puddle.
I've left carbs at work hooked up this way... come back after a weekend and they're dry as a bone.
That's how they're supposed to be.
As for the "late seventies" bit... Not altogether true.
Many current bikes have no vacuum petcocks.
Were this leaking story true... then all those Triumphs that used to sit in the shop for months would have presented a fire hazzard.

[81xsproject]

That is what I was thinking. These are actually Suki carbs. I can tell because they only have one central fuel T. But they're early 80's carbs and certainly have Viton tipped needles. I don't think they should leak and I think he is full of it. Like I said, I can leave my XS on for days with nary a drop.

[fredintoon]

Hi proj,
I think it's that no, they shouldn't leak and no, you can't trust the bastards not to leak. For safety's sake always turn the fuel off.