Honda BF75, BF100, BF8A Outboard Motors Shop Manual, Page 26Get this manual
MAINTENANCE
SPARK PLUG INSPECTIONI ADJUSTMENT
Remove the engine cover (page 4-3) Remove the spark plug cap Remove the spark plug with spark plug wrench NOTE: Before removing the spark plugs, clean any dirt from around the spark plug base to prevent dirt or foreign material from entering the combustion chamber
Visually inspect the spark plugsDiscard the plugs if the insulators are crackedchipped, or heavily fouledCheck the spark plug insulator (1) and sealing washer (2) for damageReplace the spark plug with new one if it is damaged Measure the plug gap with wire-type plug gaugeIf the measurement is out of specification, adjust the gap by bending the side electrode (3)