fuel tap problem

[jkob]

fuel tap doesn't work on reserve on my b6 1G. i always set the tap to RES and refuel
every 135 miles or so. now, when the fuel in the tank gets to the rev level, no fuel is flowing to the carbs. no prob with ON or PRI position.
i've opened the fuel tap looking for problems in the RES filter gause, or in the RES passage - everyhing is alright.
i believe that for some reason, when the tap is on RES position, the vacuum, doesn't pull the fuel to the carbs.
any idea anyone?

[LowRyter]

my Gen 1 won't pick up the last 3/4 gallon of fuel.

[lucas]

Hi,

my b12 does the same thing. But if I open the tank and let air in then it works. It seems to be some kind of vapor lock problem. What I do is keep at least a couple of gallons of gas in it at all times. I have found no other solution except to open the tank when it runs out of gas which is a PIA. I think I have read of this problem on other Bandits on the Forumn.

Lucas

[jkob]

hi lucas,
i think you're  right, this is the problem.  but  there must be an other solution except opening the fuel cup. when i find something,i'll let you know.did you try to open and clean the cup? maybe dirt and etc' are blocking the air flowing in/out .

[Rocketjock]

Just a note on the petcock. My 06  is the first I've ever had with a completely automatic petcock. You turn the engine over, diaphragm opens and fuel is delivered. I like it. No fuss, no muss. I think the manual petcock is a holdover from the biplane era and has finally gone that way. My digital gauge gives me two different warnings when it's time to fuel up and I have no problem with that. I have both rebuilt and replaced previous petcocks with the price ranges barely differing and still remember some that would barely turn and others that always leaked. For the cost, if this one screws up in a few years, I'll just replace it.

[okbandit]

I have had the mystery fuel lock up in my 2001 b12.  After much experimentation and part changing (a little cursing too) I am closing in on the cause.  Under the fuel door is a little orange piece of rubber that vents the cap.  I pulled mine off and stuck it in my pocket on the side of the road and have had zero problems since then.  I switched out the cap with a known good one from my other bike and that is definitely my problem.  I don't understand it yet, but it is something to try, and a little easier to live with then the open fuel door on the road.  Mine would lean out and eventually die with the lid closed.

[wiredgeorge]

Newbie owner here and don't  yet have a shop manual. Have most of the chapters downloaded in pdf form but I hate looking at stuff online when the bike is at my shop...

there are two hoses under the tank near the fuel level sender unit. What are these hoses for? I suspect one might be an overflow in the event the seal on the sender goes and it starts leaking... wouldn't do to have gas dribble on a hot engine. But what is the other? If it is a vent (cap also vents), then if it is pinched ANYWHERE along its run down under the bike, you might get a full or partial vacuum lock in the tank. It isn't a full lock as this would cause the tank to implode bwhahaha

[CWO4GUNNER]

[Red01]

George, one hose is a water drain from the filler, the other is a vent hose.

Gunner, the petcock turns off in the ON & RES positions whenever there's no vacuum signal supplied to the petcock. So you can run the carbs out of gas like you used to do with the old manual petcocks, all you have to do is remove and plug the vacuum hose from the petcock.

[Bob Holland]

If you are having petcock problems, Pingel sells a petcock that is just on and off. The one I have has no reserve, so you have to keep a close watch on you mileage, so as not to run out of gas.