Motorcycle Repair: Kawasaki carb. not shut off - fuel leak, rubber cone, float bowl

Question
Have 79 KZ400 - needles in carbs were not shutting off when
sitting.  pulled carbs / cleaned out / new needles / clips/ floats. Seats are not replaceable.  Still leaks. Any suggestions as to what to look for next. ?

Answer
Your floats are sticking, probably due to the float seat... it should have a rubber cone on the end of it that shuts off fuel flow when the floats rise. If there is debris in the float bowl it will get stuck in this area causing the problem you have described.