Shindaiwa EB221S Operator's Manual page 24

Maintenance and care
Check spark plug
a: 0.6 - 0.7 mm
Tools required: T-Wrench, Feeler gauge
Parts required: Spark plug
IMPORTANT
Use only NGK BPMR7A spark plug otherwise severe engine
damage may occur.
1. Check plug gap. Correct gap is 0.6 mm to 0.7 mm.
2. Inspect electrode for wear.
3. Inspect insulator for oil or other deposits.
4. Replace plug if needed and tighten to 15 N·m - 17 N·m (150
kgf·cm to 170 kgf·cm).
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