Older model Briggs & Stratton small gasoline engines with breaker point/condenser ignition systems can be converted to a modern breakerless electronic ignition. Briggs & Stratton offers conversion kits for most of its old-model engines. You can purchase these kits from lawn and garden equipment dealers, hardware stores and home centers, or order from the company itself.
Disconnect the spark plug lead. Snap off or unbolt the shroud covering the flywheel; remove it. Undo the two bolts holding the coil armature in place, using a socket wrench. Pull off the armature’s grounding wire, which usually is attached to one of the hold-down bolts. Lift the armature off the engine.
Cut the armature’s primary wire leading to the ignition points and the wire coming from the engine’s stop switch as close to the flywheel as possible, using wire cutters. Remove the flywheel with the flywheel puller. Discard the flywheel key. Remove the dust cover over the points. Remove the points, condenser and point plunger. Plug the plunger hole with the plug in the conversion kit. Trim the armature’s primary wire to a 3-inch length with the wire cutters. Strip 5/8 inch of insulation from the end of the wire with a utility knife. Scrape the insulating orange varnish off the exposed wire with the knife. Avoid nicking or cutting the wire.
Install the electronic conversion module. Look at the coil armature from the top. Locate the left leg. Snap the module into place on the underside of the left leg.
Clamp the pin punch into the bench vise. Open the spring-loaded wire retainer that’s at the end of the module pointing away from the flywheel by placing the opposite end of the module over the pin punch and pushing down until the wire retainer opens. Insert the primary wire from the armature, the primary wire from the ignition module and the wire leading to the stop switch through the retainer and let it snap shut. Solder the wire ends together.
Twist together the ground wires from the armature and ignition module. Solder the twisted portion. Remove the shorter of the ground wires by cutting it off close to the soldered connection. Don’t allow the ground wires to touch any other wires. Coat the ground wires with silicon sealer.
Reinstall the flywheel with a new key from the conversion kit. Reinstall the armature. Place the ground wire terminal under one of the retaining bolts and thread the bolt in hand tight. Thread the other bolt in hand tight. Turn the flywheel until the magnetized portion faces the armature. Insert the shim between the armature and the flywheel to provide clearance. Tighten the armature hold down bolts. Remove the shim.
Check that the modified armature does not interfere with the air vane governor and other moving parts. Reinstall the flywheel shroud. Attach the spark plug wire to the terminal on the spark tester and the tester’s alligator clip to an engine bolt. Turn the stop switch to the “run” position. Crank the engine. A spark should appear in the tester. Turn the stop switch off. Crank the engine. No spark should appear. Reattach the spark plug lead to the plug.