Carburetor pitcock setting

[79xs650rider]

Hey guys im new to the xs650 great bike I have been read alot of the threads but cant seem to find out were to set the pit cock it has pri.. that must be prime.. on... thats were i run it... then there is res.. is that reserve.. it has the vacuum tube from the pit cock to the the carb holder what is this for...Thanks.... JD

 

[Hairyblackdude]

The petcock is vacuum controlled... It doesnt let gas thru unless the motor is running.

ON- normal setting. You should leave it like this.

PRIME- ON, all the time. Used to refill the carb bowls, if drained, w/o having to start the bike then set back to ON.

Reserve- Kinda obvious.

 

[79xs650rider]

Thanks thats what i was thinking just double checking I must have a problem in my pilot circuit cause it will run with in the prime with the vacuum plugged when its in the on it will pop throw the right side.... JD

 

[anysnail]

Thanks thats what i was thinking just double checking I must have a problem in my pilot circuit cause it will run with in the prime with the vacuum plugged when its in the on it will pop throw the right side.... JD

i think you are having the same problem i had at first but i can't really understand what you are saying.

you might try adjusting the idle fuel mixture on the carb. they run real lean and that could be causing the backfire. also it will run with it on prime cuz prime just pours gravity fed gas into your carbs.

 

[79xs650rider]

What im trying to say is when it is set to prime and i cap off the vacuum line it will run...but if I hook up the vacuum tube and set it to on it pops on the right side I tried adjusting the idle fuel mixture screw the more I turn it out to richen it pops more...JD

 

[gentlemanjim]

Petcock is shot if it only runs on prime PRI

 

[XSLeo]

It could be a bad vacumm hose from the petcock to the vacumm barb. A bad hose can have an air leak, leaning out that side.

 

[79xs650rider]

Found it small cracks in vacuum hose..... good call XSleo thanks.....JD