Toro 139-0720 Lawn Mower Ignition Coil Assembly

The Toro 139-0720 Lawn Mower Ignition Coil Assembly is designed to provide the ignition spark required for compatible Toro mower engines. When this coil assembly develops wear or electrical failure, the engine may experience starting problems, misfires, or inconsistent operation due to interrupted spark generation.

Common Issues:

• Engine cranks but does not ignite due to missing spark output.

• Engine stops suddenly after reaching operating temperature.

• Weak spark causes rough running and reduced engine performance.

• Ignition coil wiring or terminals develop connection problems.

• Damaged coil assembly prevents consistent spark delivery.

No Spark From Ignition Coil

Quick Check: Inspect the Toro 139-0720 ignition coil wiring, terminal connections, and spark plug lead for damage or loose connections.

Fix Suggestion: Inspect coil connections, confirm proper grounding, and verify the flywheel air gap before replacing the ignition coil assembly.

Prevention Tip: Keep the ignition coil area clean from oil, grass debris, and moisture buildup.

Engine Shuts Off After Warming Up

Quick Check: Test spark output when the engine is warm to identify heat-related ignition coil performance problems.

Fix Suggestion: Test the ignition system when the engine is warm and replace the coil assembly if heat-related failure is confirmed.

Prevention Tip: Maintain proper engine cooling airflow to reduce excessive heat exposure around ignition components.

Incorrect Ignition Coil Air Gap

Quick Check: Inspect the distance between the Toro ignition coil and flywheel magnets for incorrect spacing or misalignment.

Fix Suggestion: Adjust the coil position to the recommended air gap and tighten mounting screws securely.

Prevention Tip: Verify coil alignment whenever servicing the flywheel or nearby engine components.

Damaged Coil Housing or Wiring

Quick Check: Examine the ignition coil body, spark plug wire, and insulation for cracks or physical damage.

Fix Suggestion: Replace the ignition coil assembly if damaged housing or wiring prevents consistent spark generation.

Prevention Tip: Avoid pulling on ignition wires and protect the assembly during engine maintenance.

Customer Experience: After installing the Toro 139-0720 ignition coil assembly, my mower regained consistent spark and started reliably again.