Walk Behind Lawn Mowers

I purchased an awd mower model LC221A last june to be used as a trim mower only. Used it maybe 4 times and less than 2 tanks of gas. I then drained the tank and stored it. When i tried to use it this year it started but would not continue to run. I took it to Naylors Ace in Cumberland MD has been there over 2 weeks. When. I checked on it they told me it needed a float and was waiting on it. My question is how can a new mower slightly used need a new float?