Briggs and Stratton Problem

I have a Briggs and Stratton engine Model 111P02-0005-F1, this engine will not start unless you put carburetor cleaner, or hold your hand over the carb for extreme choking, when it starts it runs beautifully, I feel if it had a full choke plate it would fix the problem, but I am open to any suggestions. the 3/4 choke plate worked for 3 years.