Petcock for two-bolt gas tanks 2007-2013 vacuum operated

This is the OEM original-style fuel valve. In the "on" and "reserve" positions, it flows only when engine vacuum is present. That's the hose from the top of the left carb up to the small nipple on the fuel valve. In the "prime" setting, fuel flows no matter what -- it's for priming the carbs for a few seconds before switching back to one of the other positions.

I like the automatic petcock. Some people seem to think these always fail, but honestly it takes something like a decade, assuming you ride every month or two.

These are pretty easy to rebuild, too, so if you have one already, there are cheaper options to making one work properly again.