Honda BF35A-BF45A Outboard Motors Shop Manual., Page 267Get this manual
2SERVICE INFORMATION ITROUBLESHOOTING
EALERT SYSTEM (Remote control type)
When the engine running over 3,OOOmin -I(rpm) warning horn sounds and rpm drops while running
Continuous sound
Check the indicator lampsN0
N0 Overheat lamp (red) is ONOil pressure lamps (green) is offNOTE: NOTE: If the overheat turns ON If the oil pressure light turns OFF when restarting the engine after when the engine speed has suddenly YES performing hot soak, then turns slowed down, then turns ON after OFF after idling for couple of idling for or minutes, operation is normalminutes, operation is normalYES Stop the engine and check the oil levelIs the oil level corect? Stop the engine and check the water intake port for cloggingIs the water intake clogged?
Check the CDI unitNo problem if the thermo switch wire {red) is disconnected
No the pressure switch wire (yellow) disconnectedYES Check the pressure switch
Low oil level