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.
Screw (19/32" Long)
Screw (air cleaner primer base)
7/16" Fuel line clamp
Flange Bolt (Muffler)