Champion Spark Plug (RC12YC). 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.
Grass bag frame. If the grass bag is dragging on the ground, or the frame will not stay in position it may be broken or bent and will need to be replaced.
Lower handle bar. There are two sets of holes in the bar. The one closest to the flat end is used for shipping. You will use the mounting hole furthest away for normal use.
Lawn mower blade adapter. If the lawn mower's blade isn't engaging properly, the blade adapter may be stripped. If the blade adapter is stripped, replace it.