When Flywheel Magnets Weaken after Impact or Heat

A demonstration field guide for magnets that no longer fire a borderline coil using magnet pull compared with a known-good flywheel before replacing the flywheel.

This demonstration guide answers one field question about magnets that no longer fire a borderline coil. Measurements come before parts, and the notes are not a generic equipment FAQ.

Diagnose before replacing parts

Start with magnet pull compared with a known-good flywheel. That reading separates magnets that no longer fire a borderline coil from adjacent faults that share the same complaint.

If the measurement is out of spec, treat the flywheel as the primary path. If it is in spec, do not replace the flywheel just to complete a parts list.

Repair the failed system

The usual correction is the flywheel, installed to the documented spec for this complaint.

A demonstration shop records the finding so the next technician is not repeating a guess about magnets that no longer fire a borderline coil.

Stop before you make it worse

Do not stacking extra magnets onto a cast flywheel. That shortcut hides the original measurement and creates a second failure.

If the machine still fails after the flywheel is corrected, convert the visit to a broader diagnosis rather than stacking parts.

Written and published by Ridgeline Small Engine.

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