1997 yamaha S200TXRV

[Goliat81]

I buy three thermo sensors, I install the main thermo sensor treader by the spark plug on the left side of the engine, but can some body tell me where locate the other two, looks like I have to push in because no have screw, but also I check the diagram but no looks clear.

[boats.net]

They plug into hole on top of each cylinder head