1998-2006 Yamaha F20/F25 Outboards Service Manual, Page 391Get this manual
IGNITION CONTROL SYSTEM
LOW-OIL-PRESSURE WARNING LAMP
1Check: LED (light emitting diode) Does not light 7 ReplaceBattery voltage: 1.5 YellowRed lead 7 Positive terminalPinkWhite lead 7 Negative terminal
Only use penlight battery (1.5V) when checking the LEDOther batteries (e.g alkaline batteries, high-voltage batteries) will damage the diodeNOTE: _