Why do mower backfire while running?

Mowers backfire while running primarily due to incomplete combustion, which can occur from a few common issues. These include a dirty air filter, improper fuel mixture, or a malfunctioning spark plug. Additionally, backfiring can happen when fuel ignites in the exhaust system, often due to a timing issue or a buildup of unburned fuel. Regular maintenance can help prevent these problems and ensure smooth operation.