hi remove carb ,undo the phillips screws securing the float bowl and remove.remove the pin securing the float and lift the float out,.carefully inspect the float for leaks,give the float a shake and see if you can hear petrol inside the float chamber.the float chamber snould be free of petrol inside.you will notice a small tab that covers the float jet.inside the brass jet you will find a float level valve with a small spring loaded pin in the center of it.make sure this pin is not stuck down in the body of the valve.make sure the spring pin is coming into contact with the tab on the float.this valve determines the amount of fuel in the float chamber.too much fual due to a incorrectly set float height or failure of the above mentioned will result in fuel being forced out of the overflow pipe.get yourself a haynes workshop manual .it will show you step by step illustrations on how to remove,inspect and correctly adjust the float height .the fuel tap is only a means of supplying the carb with fuel. the float operation and correct adjustment determines the flow to the carb.
mech monster, November 2011