Small Engines (Lawn Mowers, etc.): lawn mower wants to stop running, gas tank, gas cap

Question
I have a 22 inch lawnboy push mower. When the gas tank is full the mower runs good until it gets to about half a tank it wants to stall and sometimes does

Answer
 Hello Patrick:

 Send me the Model Numbers Off of the Mower and Off of the Engine, Please. With these I can See the Engine and the Mower and can Better Assist you. However, Remove the Gas Cap and Ensure it is Venting the Gas Tank Properly. Thanks.

 Respectfully

 John