1998-2006 Yamaha F20/F25 Outboards Service Manual, Page 383Get this manual
'IGNITION SYSTEM
IGNITION SYSTEM PEAK VOLTAGE
A WARNING
When checking the COl unit, do not touch any of the connections of the digital tester leads
1Measure: CDI unit output peak voltage Above specification Replace the ignition coilOutput peak voltage: BW-O rmin Cranking Opened 200 Closed 180 1500 190 3500 190