1. No fuel in tank. Fill tank with clean, fresh fuel.
2. Shut-off valve closed. Open valve.
3. Obstructed fuel line. Clean fuel screen and line. If necessary, remove and clean carburetor.
4. Tank cap vent obstructed. Open vent in fuel tank cap.
5. Water in fuel. Drain tank. Clean carburetor and fuel lines. Dry spark plug and points. Fill tank with clean, fresh fuel.
6. Engine over choked. Close fuel shut-off and pull starter until engine starts. Reopen fuel shut-off for normal fuel flow.
7. Improper carburetor adjustment. Adjust carburetor.
8. Loose or defective magneto wiring. Check magneto wiring for shorts or grounds; repair if necessary.
9. Faulty magneto. Check timing, point gap; if necessary, overhaul magneto.
10. Spark plug fouled. Clean and re-gap spark plug.
11. Spark plug porcelain cracked. Replace spark plug.
12. Poor compression. Overhaul engine.
13. No spark at plug. Disconnect ignition cut-off wire at the engine.
14. Crank engine. If spark at spark plug, ignition switch, or safety switch interlock switch is inoperative. If no spark, check magneto.