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How to Replace a Coil on a Briggs Engine

bushhog tractor attachment image by Kathy Burns from

Briggs & Stratton has been successfully building small engines since 1908. Lawn equipment such as tillers, push lawnmowers, riding lawn mowers, and weed eaters have used Briggs & Stratton engines as their primary means of power. Briggs engines provide a lot of power in a small package. Even though these engines vary in size, their basic construction and design is still the same.

Remove the spark plug.

Remove the three or four screws that hold the top flywheel cover housing in place and remove the housing.

Use your feeler gauge to determine the air gap between the flywheel and the existing coil. Record this measurement. It is a good idea to check the Briggs & Stratton repair manual to verify the proper setting of this gap.

Unscrew the bolts that hold the coil in place and remove it. Place the new coil in position and tighten the bolts finger tight.

Turn the flywheel until the magnets on the flywheel are in front of the new coil. Place the correct size feeler gauge between the flywheel magnets and coil. Squeeze the feeler gauge between the coil magnets and the coil.

Tighten the coil screws using your socket wrench and remove the feeler gauge. Rotate the flywheel one complete revolution to verify that the coil and flywheel do not make physical contact with each other.

Replace and tighten the flywheel cover housing. Replace the spark plug and reconnect the spark plug wire. Start the engine.

Test A Briggs Coil

Keeping a good running engine depends on good fuel, mechanical and ignition systems. Problems can sometimes occur that point to a bad ignition system. Most later models use Briggs and Stratton's magnetron coils—essentially a self-contained ignition system that derives its power from the magnets on the flywheel. Clip the spark tester to a clean metal part of the engine. If you do not see a spark as the engine spins, proceed to Step 2. Measure the resistance on the circuit you've just created. A normal reading ranges from 2,500 to 5,000 ohms.

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