What to do if my Toro Z Master Professional 5000 engine will not start?
- DDavid MillerAug 28, 2025
If your Toro Lawn Mower engine won't start, starts hard, or fails to keep running, several factors could be at play. First, ensure the fuel tank isn't empty and the fuel shutoff valve is open. Check that the oil level in the crankcase is adequate. For a cold engine, make sure the throttle control is midway between the “SLOW” and “FAST” positions, and the choke is in the “ON” position; for a warm engine, the choke should be “OFF”. Also, inspect the fuel filter for dirt and clean or replace the air cleaner element if it's dirty. Check the seat switch indicator and replace the seat if needed. Inspect all electrical connections, clean connector terminals, apply dielectric grease, and reconnect. Clean, adjust or replace the spark plug and check the spark plug wire connection.






