Small engine Champion spark plug (RJ19LM). If the engine does not start, the spark plug may be defective. The spark plug should be replaced periodically during regular maintenance.
Tecumseh ignition coil (also called a lamination). The ignition coil sends voltage to the spark plug while the engine is running. If the ignition coil is defective, the engine may not start.
Tecumseh air cleaner (or air filter). If the air filter is clogged or dirty, the engine may not start or may run rough.