how can you tell if its broken mine turns by it self when the bike it on and cuts the fuel on me i have to pay with the switch to keep gas going

 

That's a pretty good indication. Mine kind ofclicks into place if that makes sense. Check the sscrew going into the selector, if it's too loose I would imagine it would do the same. You may look into replacing it. I bought mine off eBay for like 19 dollars. Came with a screen and works perfect.

 

i bought a oem one from ebay for 30

 

and it does clink wgn i change positions

 

The "clicking" is done with a ball bearing with a spring pushing on the ball so that it locks the handle into place. So maybe the spring inside the petcock is worn?

It definitely shouldn't turn by itself while riding.