Champion spark plug (RCJ6Y). The spark plug ignites the fuel and air mixture in the engine's cylinder to power the engine. If the spark plug is has fouled (if the tip of the spark plug is burnt or damaged), the engine may not start or may run rough.
Nut hex flange
Nut-Locking. The manufacturer has changed vendors and the part may vary in character. Some do not have a nylon insert, however the nut is a locking type.
Washer 3/8 Splt Lock
Husqvarna nut, 3/8-16.
Washer thrust 5/8x1
Flat washer 1/2" x 1-1/2" x .134