1985 70 ETLK temp sensor in head or near thermostat?

[Velzynh75]

Hi.

I have a 1985 Yamaha 70hp ETLK. There are two sensors with wires in the area of the cyl head. One is is rubber with a metal end and sits in a pocket in the head (external) and has pink and black wires. The other is next to the thermostat and screws in and has blue and black wires. I am hoping someone can shed some light as to what both do. I am assuming temperature but didn't know which does what. the wires have been cut previous to my ownership.
Thank you in advance.
Ryan

[boscoe99]

Pink and black are for the thermoswitch, which comes with the motor. It closes when the head gets to a particular temperature.

Black and blue are for an optional temperature sender that runs to an optional temperature gauge.

[Velzynh75]

Thank you very much. That helps a lot!
Ryan