Honda BF20A-BF25A, BF25D-BF30D Outboard Motors Shop Manual., Page 197Get this manual
HONDA BFSOASSA
CHARGE COIL 12V-10A (12V-10A Charge coil1 Electric starter type only)
Measure the resistance between each terminal of the charge coil kit with the tester
Resistance
IGNITION COIL
NOTE For ignition coil replacement, see page 16-3Primary side resistanceMeasure the resistance of the primary coil between the terminals at the igniton coil