1985-1986 Honda Fourtrax 125 TRX125 Shop Manual, Page 212Get this manual
PULSE GENERATOR,
IN SPECTION
DisconneCt the pulse generator wire cou plerMeasure the resistance between the green and bluel yellow wiresRESISTANCE900hml Replace the pulse generator if the reading IS not within the lim it See page -3 for pulse generator replacement