Briggs & Stratton Spark Plug (RJ19LM). If the engine does not start or runs poorly then the spark plug may be defective and will need replacement.
MTD Spark Plug. The spark plug ignites the fuel and air mixture in the cylinder to power the engine. If the spark plug is burnt, fouled or damaged the engine may not start or may run rough.
Champion Spark Plug (RH10C)
Ngk spark plug br6s