1999 Kawasaki VN1500G with CVK 40MM carb spilling excessive fuel.
The issue: I treated gas with fuel stabilizer but failed to start motor to ensure that treated fuel circulated into carb and fuel pump. As a result, hardened residue (shellac) flowed from fuel pump into a clean carb which jammed float valve open thus causing an excessive amount of gas to exit carb and flood motor at all speeds.
Purchase: fuel pump/filter, carb cleaner and carb rebuild kit (all balls performance).
Disassembly: using spray carb cleaner, clean carb thoroughly; followup with compressed air to ensure that all openings and fuel lines are clear of debris.
Assembly: assemble carb properly, calibrate float height (18mm) and set idle mixture screw to spec. Install fresh fuel filter and new fuel pump. Change engine oil if excess fuel condition has flooded cylinders.
Lesson learned: if you treat fuel with stabilizer, ensure that you operate motor so as to move treated fuel into pump and carburetor float bowl. Old fuel residue can cause issues even after cleaning carb.