Depending on the specific magneto model you are working with, different manuals will be applicable. The following is a detailed catalog of manuals divided by common use cases and model series.
Inspect the contact surfaces. They should be smooth and free of excessive pitting, oil, or white oxidation. Electrical Testing
The Complete Guide to Scintilla Magnetos: Operation, Maintenance, and Troubleshooting
Detailed processes for dismantling, inspecting, and reassembling the magneto. scintilla magneto manual
Seal the magneto housing or the entire engine assembly in a plastic barrier bag with desiccant packs. Moisture will degrade the fine wire insulation inside the secondary coil over time.
The unit should be kept free of dirt, particularly around the distributor cap and breaker points to prevent tracking or misfires. 4. Troubleshooting and Rebuilding
Loosen the breaker assembly retaining screws. Connect a magneto timing light (buzz box) across the points. Adjust the points so they just begin to open at the exact moment the rotor hits the E-gap position. Tighten the screws and re-verify. 5. Magneto-to-Engine Timing Depending on the specific magneto model you are
When the engine turns the magneto, the rotating magnet spins within the coil, generating a magnetic field. This field induces an electrical current in the coil, which is then stored in the capacitor. When the capacitor reaches a certain voltage, it releases the energy in the form of a high-voltage spark, which is then sent to the spark plug to ignite the fuel.
Turn the shaft until the points are at their widest clearance. Check with a feeler gauge. Standard Scintilla point clearance usually falls between 0.0120.012 0.0150.015
Over-oiling is the leading cause of magneto failure. Use a specialized high-temperature cam grease on the breaker cam, but only a tiny, "matchhead-sized" amount. 4. Troubleshooting Common Issues Likely Cause Grounded "P-lead" or fouled points. Disconnect the kill switch wire to isolate the mag. Weak Spark Weak internal magnet or aged capacitor. Test magnet strength; replace the condenser/capacitor. Engine Kickback Timing too far advanced or impulse coupling sticking. Retime the mag to the engine; clean the impulse springs. Misfire at High RPM Points bouncing or worn cam lobe. Check point tension and cam wear. 5. Safety Warning: The "Hot" Magneto They should be smooth and free of excessive
Per manual, mark the magneto flange position relative to the engine case to preserve timing. Remove the two flange nuts.
: Consists of the rotating magnet, the pole shoes, and the core of the coil. The Primary Circuit