Does anyone know the proper way to use the petcock? Are you supposed to turn the gas off everytime you park for awhile or only when working on your bike?

 

The only time mine was every turned off was during Winter storage. Never had a single problem.

I believe relatively new models have some sort of float valve, or vacuum which makes it safe to leave the gas on. I'm sure someone can explain it better than me.

 

On my old 91 Springer I just made it a habit to close it every time I parked. It doesn't take much for just a small piece of trash to hold the float needle open which could cause gas to leak through the carb. I had a carb on it at one time that just the leaning of the bike on the kick stand would cause the float to let gas continually flow. If I tried to adjust it it would have to low of a float level. Needless to say it was very touchy. The newer fuel injected bikes don't use petcocks.

 

if you leave the fuel valve on when the bike is parked, it can/will flood from time to time, the problem with it flooding besides the mess, is the gas on the floor will evaporate before you see it, but it will also run into the cylinders then wash down and dilute the oil,causing the engine to run dry..it causes cylinder and bearing wear/failure.. no warrenty will cover it if they figure out what caused it (smell fuel in the oil).. i have had to rebuild my shovel and literley dozens of rice bikes at work from the valve being left on all the time..the owners manuel says to turn off the valve when the engine isnt running..

 

Newer Harleys used a vacuum operated petcock. If it is working properly it's fine to leave it on all the time. No vacuum from the running engine= no fuel.

 

What 'e said. If it's a later bike with the vacuum op petcock leave it on it'll be fine, there's no way fuel can flow unless the motor is running.

Derv