Had issues with the mower recently (many, many issues) among which was a problem with gas getting into the oil and flooding the firing chamber.

Had to run down the issue online, which was a royal pain in the keister.

Here is the operator's manual for the engine. It wasn't really helpful but could be helpful at some point.

The file is in Adobe PDF format, and requires Adobe Reader or compatible.

Operator's manual for 14.5 HP Briggs and Stratton engine. (PDF)