07 was running fine, but now idles then dies, will restart if it sits for a few

[mr72]

No matter what position the petcock is in fuel flows because of gravity. Vacuum just opens the valve automatically while prime opens it manually. There is literally no way it can behave differently.

And on top of that the float valves should shut off fuel when the bowl Is full regardless of angle.

[Darkstar]

Vacuum just opens the valve automatically

Interesting, there's a valve in the petcock that gets triggered by vacuum?

[Kookas]

Vacuum just opens the valve automatically

Interesting, there's a valve in the petcock that gets triggered by vacuum?

Yep, there's a valve in there which is sucked open by the vacuum, through the narrow hose coming out the back of the petcock.

[Darkstar]

Yep, there's a valve in there which is sucked open by the vacuum, through the narrow hose coming out the back of the petcock.

That's a smart design, thanks. Looks like I was wrong then. More importantly, I discovered that my left float is 1/4" above the line, so it was running rich. Also found some fuel in my airbox but that's because I was testing with a remote tank connected to carb fuel line, bypassing the petcock.

[5thAve]

Always start with the simple stuff first. Have you topped off the tank with fresh gas? I've had these same problems when I got a tank of bad gas. Ran fine but wouldn't idle. Draining some and topping off with gas from a different source is an easy solution to try before you start looking for bigger problems.

Sent from my ONEPLUS A5000 using Tapatalk

[mr72]

 More importantly, I discovered that my left float is 1/4" above the line, so it was running rich.
[/quote]

This also explains the overflow condition.