fuel overflow

I went to see to buy a gs but it had a weird problem.

the owner had the tank filled up (3/4) right before i was there.
the engine started oke and kept on running oke for a while . when we shut it down there started to drip fuel from an overflow tube on the side .we than started the motor again but it went a bit difficult. we got it runnig again , and it stayt on whitout a problem . but when we shut it down the dripping fuel was there again .

now the obvious question is ,what is causing this? could it be enough to do some maintenance on the carb?

thx in advance.
PS sorry for speaking in English ,but I am from Belgium so I don't speak German.

[Kunibert Babenco]

Hi Senna!

I think the overflew tube where the fuel dropped out is the airbox-drainage.
When a float needle valve in the carburetor is broken, the fuel-level in the float chamber gets too high an it overflows into the airbox.
The fuel can also get into the cylinder and, past the piston ring, into the crankcase where it dilutes the oil - not good.

this would also explain your problems to start the engine again.

But all this can only happen, when the fuel cock (it's really named "cock"?? ) is in "pri"-position or not functioning correctly.

Hope i could help you,
greetz
Pat

so if i get this correct it really is a problem with the carburettor.
and probably the problem would be solved if i would buy this:
http://www.louis.de/_406d53a3e4deae5...nr_gr=10042430

when the fuel cock is in "pri"-position or not functioning correctly.

this is the only part I don't understand . what is a fuel cock?

thank you for your help .

[Jais]

You can say fuel tap, too.

#1 is the part.

There you can change the positions from ON over PRI to RES.

http://alpha-sports.com/spst/1995%20GS500E/27.gif

so if i put the tap (or switch) on "ON" it shouldnt drip fuel from the overflow ?

what is the difference between "ON" and "PRI". why would it drip fuel while on "PRI" and not when it is on "ON"

[Jais]

In the fuel tap is a low-pressure valve that will open, when the engine is still running.
If the engine is off, the valve is closed like "Off" Positions from different fuel taps.

The "PRI" function goes around these valve and floods the floatchamber without the running engine.
Normaly these flooding will stop from the valve needle.

On these picture it is #33
http://alpha-sports.com/spst/1995%20GS500E/06.gif