Motorcycle Repair: fuel leak runs only for a while, kowasaki, fuel needle

Question
my 1989 ex 500 kowasaki  has 4000 miles on it. it starts easily , idles . sometimes misses when starting to give it more gas as u give it more gasit catches and runs ut gas runs out a small hlack tube at the bottom of the frame,. this is a fair amount of drainage. the drainage continues after engine is cut off. what could be the prolem.How do i do the repair myself

Answer
The fuel needle and seat valve is not shutting off properly.The brass seat is not replaceable however you may need to polish it. Pull the carbs off and remove the bowls and floats make sure the spring loaded plunger end of needle is not stuck and springs in and out.Take some semi-chrome polish on a Q-tip and spin it inside of brass seat,clean out polish and put float back on. Hold the carb with the veturi air/fuel passage up and down the float will be on the side. Slightly tip the carb back untill the float needle just touches seat this will give you a static float height.If float is parallel with carb bowl surface this will work if not bend the small tab over the needle to get it so. Put bowl back on. Put carbs back on bike and try again.