If no spark occurs, refer to qualified service person. If spark is present attach spark plug to wire and ground the base of the plug to the cylinder head. A spark should jump the plug gap. If no spark, clean and gap spark plug. If still no spark, replace plug.
Engine fails to start but compression and spark are adequate remove air cleaner.
If engine starts choke is inoperative or fuel blockage has occurred. An engine with good compression, spark, and fuel delivery should start. Develop a list of uses for small engines. Provide students with equipment and manuals. Students can review manuals, start and operate equipment, and make a presentation to the class on the appropriate pre-operation check, starting, operation and safety.