Honda BF75, BF100, BF8A Outboard Motors Shop Manual, Page 116Get this manual
CONSTRUCTION AND FUNCTION Neutral Switch (Engine serial number 1300001 subsequent) neutral start system prevents the engine from starting when the shift lever is in the FORWARD or REVERSE positionThe system neutral switch consists of lead switch on one side and magnet on the otherA shield installed on the shaft either allows the magnetic force to reach the switch or obstruct the fielddepending on the gear selected
NEUTRAL SWITCH
LEAD SWITCH
MAGNET SH ELD PLATE
SHIFT SHAFT