how can you tell if you over heated your motor?

[skeeterman]

Can someone tell me how you can tell when you have over heated your motor?I have a 1989 yamaha 50 pro. Im not sure if i have a buzzer or not.I know i don't have a gauge to tell me.I believe my head gasket is blown because when i remove the bottom spark plug and crank it water is spitting out the plug hole.And im hoping i didn't do any damage the other day.She will fire right up no problems starting.I didn't notice any steam or anything coming from the motor.But i was wondering what are the signs of a outboard thats been ran hot.Its easy for a car there are signs like radiator smoking.But im new to this boat thing and im not sure what to look for thanks for any replies .Im also going to do my head gasket myself.Any tips on doing that would be helpful also.Sorry for so many questions guys.But im sick worrying about this motor thing guys please be patient with me.Also does anyone know what the torque is for the head ?