Once you have the model number, you can:
* Check the owner's manual: This is the most reliable source.
* Look up the model number on the Briggs & Stratton website: Their website has a parts lookup tool.
* Contact a Briggs & Stratton dealer or repair shop: They can help you identify the correct plug based on your engine's model number.
Without the model number, any recommendation would be a guess and could potentially damage your engine.