PRI,RES OR ON??

I just bought an 82 xj550. After I shut the bike down what should I switch the lever to? pri,res or on?
thanks in advance
Joe

 

you can leave it on ON. it is vacuum operated so it won't leak when the bike is off and the petcock is left on.

 

when should I have it on PRI or RES? I left it on PRI and parked the bike and it seems like some gas was leaking from somewhere.

 

You put it on REServe when you're bopping down the road and your engine starts to sputter because you're low on gas.

You put it on PRIme when the bowls in the carbs have been emptied for some reason and they need to be refilled.

If the carbs are in good working order, then the float needles in the carb bowls will keep any more gas from coming into the carbs than there needs to be. If this isn't happening, then you might have gas draining into the crankcase, and that's BAD.

 

PRI (prime) lets the fuel flow no matter what - in standard non-vacuum operated mode. If you've got fuel leaking from somewhere if it's sitting in that position then you've likely got a stuck or badly fitting float valve.

ON is just the main position, vacuum operated, giving you the majority of the fuel in the tank.

RES is the Reserve, vacuum operated, and gives the remainder at the bottom of the tank.

 

Long story short, don't leave it on PRI

 

PRI is for PRIME. Just incase you did not know. This over rided the vacuum operation when in the ON position and will supply a continuous flow of gas to the carbs. If you have work float needles or seats, this will result in flooding. RES, reserve, makes no bit of difference then ON, except the tank pick up is at a lower level. On my bike this is close to 1/4 tank mark.

 

I've been wondering this too, but now I got answer even without asking