Troubleshoot a John Deere lawn mower by checking for common problems like clogged fuel filters, defective spark plugs and clogged carburettors. While examining these problems, look for more complex issues that require fixing.
If a John Deere lawn mower does not start, first check to make sure there is gas in the tank. Confirm that the choke is on and the engine-on switch is turned on. If the problem continues, check if the fuel filter or carburettor is clogged, and replace them if required. Additionally, examine whether the spark plugs and the ignition coils are working properly, and replace them accordingly.
If the lawn mower engine runs poorly, check whether the carburettor is blocked or has bad, old fuel in the float bowl. If the bad fuel was left in the engine for long, volatile ingredients may have evaporated, leaving a sticky, thick product that can block the small ports and jets in the carburettor. Drain the bad fuel from the float bowl, and use a carburettor cleaner to clean the carburettor. If this does not fix the problem, check to see if the engine is getting enough fuel and air, and replace carburettor kit if necessary.
If these repair methods do not remedy the issue, contact a John Deere professional for assistance.