How to Change Points on a Briggs and Stratton
Briggs & Stratton builds a line of small engines for industrial and residential uses, such as lawn mowers, pressure washers and rototillers. While newer engines use a solid-state ignition system, older models employed points and a condenser underneath the flywheel to generate spark for the spark plug. If one of these older engines isn't generating spark to ignite the fuel mixture in the cylinder, you may need to change points on the Briggs & Stratton engine.
Disconnect the spark-plug wire from the spark plug.
Remove the bolts that hold the starter housing onto the engine, using a socket set. Lift the housing off of the engine and set aside.
Position a flywheel holder over the flywheel, with the hook between the fins. Place a clutch-removal tool over the clutch and rotate it counterclockwise while holding the flywheel with the flywheel holder. After the clutch is loose, spin it counterclockwise off of the threaded crankshaft and set it aside.
Position a flywheel puller over the exposed end of the crankshaft and tighten the corresponding bolts into the flywheel. Turn each of the nuts clockwise one at a time until the flywheel pops loose. Lift the flywheel off of the crankshaft and remove the flywheel puller from the flywheel.
Remove and inspect the flywheel key. If the key is damaged, replace with a new flywheel key.
Loosen the two screws that hold the ignition cap in place over the points. Lift the cap off and set aside.
Rotate the crankshaft so that the gap between the points and condenser are at their widest point.
Loosen the screw that holds the points assembly and pull them out of the ignition housing. Remove the spade connector on the end of the wire from the spade and set the points aside. Insert the new set of points into the ignition housing in the same manner in which you removed the old set.
Remove the screw on the clamp that holds the condenser in place and remove the condenser. Insert the new condenser and tighten the screw in place.
Slip a 0.020-feeler gauge between the tip of the condenser and the tip of the points assembly. Loosen the screw that holds the points in place and adjust the position of the points assembly until it is snug against the feeler gauge, then tighten the screw to keep the assembly in place. Slide the feeler gauge out and back in between the points and condenser, verifying that the gauge doesn't widen the gap. Adjust the points if necessary, until you're confident that you have an 0.020 gap between the points and condenser.
Reinstall the ignition cap, flywheel key, flywheel and clutch (in that order.) Re-attach the starter housing onto the engine and tighten in place with the bolts.
Remove the spark plug from the cylinder head. Re-attach the spark plug wire to the spark plug and set the spark plug on the cylinder head so that the electrode on the bottom of the spark plug is not touching the engine.
Pull the starter rope a couple of times and watch the electrode on the spark plug to verify that the ignition system is now providing a good spark.
- Socket set
- Open-end wrenches
- Flywheel holder
- Clutch tool
- Flywheel puller
- Flathead screwdriver
- Feeler gauge