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.
Briggs & Stratton flywheel key. The flywheel key aligns the flywheel in the correct position on the crankshaft. If the engine stops suddenly due to hitting a hard object, the flywheel key shears in half to prevent damage to the engine. If the flywheel key is broken, the engine won't start.
Briggs ignition coil kit to replace points & condenser. 5 HP Horizontal & Vertical Series 550
Recoil starter assembly
Small engine carburetor assembly. If the engine runs rough, then the carburetor may be restricted and unable to supply enough fuel and air mixture to the engine.