I leave the petcock on all the time- if there is a leak I hopefully find it while the bike is parked, instead of getting stranded somewhere and maybe getting fuel in the oil while riding, and turning the petcock on and off every time you ride wears it out faster.
I question someone if they buy a rebuild kit for a failed petcock- it takes time to rebuild it, and you are going back to the same design that failed before. This might be best if you have an antique that will lose value if not completely stock.
A cautionary tale- if you add a bigger, better fuel filter, make sure it does not touch the petcock, so any vibration between the filter and the petcock will not damage the petcock and make it leak (been there, done that).
Last edited by ZZR600-2008; 05-07-2017 at 02:46 PM.