Cub Cadet ST 100 Operation Manual - Page 16

Troubleshooting 7 Problem Engine Fails to start Engine runs erratic Engine overheats Occasional skips (hesitates) at high speed Idles poorly Engine stalls with full tank Cause Remedy 1. Blade control disengaged (Lawn mower only). 2. Spark plug boot disconnected. 3. Fuel tank empty or stale fuel. 4. Fuel shut-off valve closed (if equipped). 5. Engine not primed (if equipped with primer). 6. Faulty spark plug. 7. Reduced fuel flow/Blocked fuel filter. 8. Engine flooded. 9. Engine not choked (if equipped with choke). 10. Burnt fuse. (Electric Start only) 1. Spark plug boot loose. 2. Reduced fuel flow/Blocked fuel filter. 3. Vent in gas cap plugged (if equipped). 4. Water or dirt in fuel system. 5. Dirty air cleaner. 6. Unit running with CHOKE (if equipped) applied. 1. Engine oil level low. 2. Air flow restricted. 1. Spark plug gap too close. 1. Engage blade control. 2. Connect wire to spark boot. 3. Fill tank with clean, fresh gasoline. 4. Turn on fuel shut-off valve. 5. Prime engine as instructed in the Operation section. 6. Clean, adjust gap, or replace. 7. Replace fuel filter as instructed in the Maintenance section. 8. Wait a few minutes to restart, but do not prime. 9. Choke engine. See engine manual. 10. Replace fuse (see Service Section of Unit). 1. Connect and tighten spark plug boot. 2. Replace fuel filter as instructed in the Maintenance section. 3. Clear vent. 4. Drain fuel tank. Refill with fresh fuel. 5. Refer to engine manual. 6. Push CHOKE knob in. 1. Fill crankcase with proper oil. 2. Clean area around and on top of engine. 1. Adjust gap to .030". 1. Spark plug fouled, faulty, or gap too wide. 2. Dirty air cleaner. 1. Carbon canister vent line(s) pinched/kinked. 1. Reset gap to .030" or replace spark plug. 2. Refer to engine manual. 1. Refer to Carbon Canister Filter Service section to remove engine shroud and relieve pinched/kinked vent line(s). Re-install engine shroud making sure vent line(s) are not pinched or kinked. 16