How Ignition Coil Air Gap Controls Spark Quality

A demonstration field guide for a gap that is too wide after flywheel service using feeler-gauge air gap at the coil before replacing the coil spacers.

This demonstration guide answers one field question about a gap that is too wide after flywheel service. Measurements come before parts, and the notes are not a generic equipment FAQ.

Diagnose before replacing parts

Start with feeler-gauge air gap at the coil. That reading separates a gap that is too wide after flywheel service from adjacent faults that share the same complaint.

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

Repair the failed system

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

A demonstration shop records the finding so the next technician is not repeating a guess about a gap that is too wide after flywheel service.

Stop before you make it worse

Do not bending the coil laminations to close the gap. That shortcut hides the original measurement and creates a second failure.

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

Written and published by Ridgeline Small Engine.

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