Is there no spark in the engine of her lawn mower, snow blower or outdoor strength equipment? follow this overview to test your ignition mechanism - including coil, switch & module - come identify any problems and troubleshoot repairs.

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If you recognize your certain problem, jump down to the ar for step-by-step instructions.

How perform Ignition Systems work-related in small Engines & Lawn Mowers? Servicing Spark Plug troubles How to check the Ignition Coil in Your tiny Engine experimentation & replacing a avoid Switch Ignition Module failure just how To check the Flywheel & Key

WARNING: always read the engine and also equipment manual(s) before starting, operating, or servicing her engine or equipment to avoid personal injury or building damage. View an authorized dealer or call Briggs & Stratton if you space unsure of any procedure or have extr questions. Discover all Engine safety Warnings

How execute Ignition Systems job-related in little Engines & Lawn Mowers?


The ignition device is the starting system for your small engine. Whether you start the engine through a traction rope or the rotate of a vital on an electrical start motor, you"re relying on the ignition system to create a spark inside the combustion chamber.

Small Engine Ignition Parts

Flywheel v magnetsCoil or ArmaturePush Button starting or traction Cords (depending on her engine type)Spark Plug LeadSpark Plugs

When you begin your lawn mower or tiny engine, you revolve the flywheel and also its magnets happen the coil (or armature). This creates a spark. The ignition system works with the time so that the spark will certainly ignite the air-fuel mixture in the burning chamber just as it reaches best compression in each engine cycle- thus, maximizing the engine power.

Once the engine is running, the flywheel keeps rotating, the magnets keep passing the coil and the spark plug keep firing based upon a certain timing.

Types the Ignition Systems

Solid-state systems: the more modern-day option, these solution use a tiny transistor in the coil or armature to close the electrical circuit the travels v the spark plug result in the spark plug(s).Breaker point systems: provided on engines made before 1980, these equipment use a mechanically switch rather of a transistor come close the electrical circuit offered to develop a spark.

Common Flywheel Problems

If you room experiencing ignition time issues, this is many often because of a sheared flywheel key. Friend can additionally test the flywheel magnets for any type of potential issues.

For information regarding this, please visit our Inspecting the Flywheel and crucial FAQ.

Common Spark Plug Problems

How To test the Ignition Coil in Your little Engine

Safety Warnings: stay clear of any rotating, relocating parts, or various other hazardous areas whenever attempting to begin the engine or equipment.

The coil is probably the simplest thing come check and also therefore the very first thing to examine when embarking top top ignition device troubleshooting.

Testing the Coil or Armature

Step 1: Clip one end of the spark tester (service component number 19368) come the ignition cable and the various other grounded to the cylinder head as displayed below.

Step 2: rotate the flywheel swiftly (at the very least 350 RPM) and watch for spark in the tester window.

If the spark jumps the tester gap, her ignition coil is working fine. If not, it requirements to it is in replaced.

Engine quits while running? Hook the tester up between the ignition cable and also the spark plug and start the engine. When it stops, monitor the window.

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Common failure When testing Coils

Be sure to unhook the coil indigenous the devices wiring harness as well as the engine"s wiring harness and use the spark tester. Many a technician is fooled into replacing a good coil due to the fact that the coil ground connection lead was shorting out versus a piece of sheet metal.DO NOT affix the tester come the spark plug because that this test. The engine might start. There is no the ground connection lead installed, girlfriend won"t be able to turn it off.

Replacing Ignition Coils or Armatures