This video shows how to diagnose and repair a Briggs & Stratton generator that has been sitting for a long time, and can't be pulled started, because the engine is locked up.

Engine Model, Type, and Spec: 21T202-0123-G1

Useful Part Numbers:
Spark Plug:
Champion RC12YC
Denso Q16-PRU
Air Filter:
491588S
Carburetor (Nikki):
591378