Engine
Starter motor does not operate or does not turn engine over
1. Engine run switch in off position.
2. Ignition switch not on.
3. Discharged battery , loose or corroded connections (solenoid chatters).
4. Start control circuit, relay or solenoid damaged.
5. Electric starter shaft pinion gear not engaging.
Engine turns over but does not start
1. Fuel tank empty.
2. Fuel supply valve turned off.
3. Fuel supply valve or filter clogged.
4. Discharged battery, loose or corroded connections.
5. Fouled spark plugs.
6. Spark plug cables in bad condition or cable connections loose.
7. Ignition timing badly out of adjustment.
8. Loose wire connection at coil, battery connection or at plug between ignition module and sensor.
9. Damaged ignition coil.
10. Damaged ignition module or sensor.
11. Sticking or damaged valve or tappets too tight.
12. Engine oil or transmission lubricant too heavy (winter operation)
Starts hard
1. Spark plugs in bad condition or have improper gap or are partially foiled.
2. Spark plug cables in bad condition.
3. Battery nearly discharged.
4. Loose wire connection at one of the battery terminals or at coil.
5. Carburetor controls not adjusted correctly.
6. Damaged ignition coil.
7. Engine oil or transmission lubricant too heavy (winter operation)
8. Ignition not timed properly.
9. Fuel tank cap system vent plugged or carburetor fuel line closed off restricting fuel flow.
10. Water or dirt in fuel system and carburetor.
11. Air leak at intake manifold.
Start but runs irregularly or misses