Petcock shut off CB 750 KZ 1979

[hocko]

CB 750 KZ
When i shut the p/cock off it does not start on the button i have to push it.I tried then left it 3 hours then i did push it. With petcock on it goes 1st time.I can leave it on all the time as i dont drip ( at  the moment). Is there a diaphram in the tap? What do you guys do. Thanks

[woodsrider250-2]

There is a vacuum operated petcock in line before the manual one on these DOHC CB's.  A lot of people remove it.

[Polymer-2]

woodsrider250 wrote

There is a vacuum operated petcock in line before the manual one on these DOHC CB's.  A lot of people remove it.

I could be wrong but I don't think 79 or 80 had the SOS. Didn't that start in 81?

[sjackson]

polymer wrote

I could be wrong but I don't think 79 or 80 had the SOS. Didn't that start in 81?

Mine doesn't have one.

[woodsrider250-2]

I stand corrected.  Mine's an '82 and I hate that thing....Coming off this winter.

So back to original question....I'm confused as to what's actually happening.