88 70 horse yammy warning buzzer

Dad bought a older skeeter with a 88 - 70 yammy that is sounding a steady buzzer after it runs a bit. shut it off afew and it runs fine but will come back on.
While this is happening the pisser is pissing strong and cool.
My question really is ,,,is a solid buzzer a oil issue or temp. I know on my merc oil is a series of beeps.
Has a new pump kit by the way also and plenty of oil in the kidney tank.
what is the method for testing a temp sensor ?

I thinnk you just check for continuity with a multimeter. I think it should be open when cold. Place the sensor in water and heat it up and check the sensor as it heats.