Just rebuild a 13B but temperature rise pass 200, friend informed me tat it could be inverter Rotors or Rotors of the same time. have change water pump, no water leaks, no smoke, engine starts fast, could be bad electric fan? Any help would be appreciated

 

Make sure the radiator is clean,also put a Mazda oem thermostat.

 

be sure the sender is the correct unit suit the gauge

early 70's rx uses different sender to late 70's / early 80s , and different again to s4,, and to s5

using incorrect sender on incorrect dash usually throws things out a lot..

for example.. a 1st gen rx7 sender put into an rx2 or rx3 will put the gauge to 3/4 at normal running temp

 

I have always wondered why my temp gauge would go up that high in my rx2.didnt think there was a difference from the oldschool units to the rx7 units.
Good info to know.

 

Install an aftermarket mechanical gauges for a second and better opinion. Back in the 90s, i fried a motor due to malfunctioning factory gauges.

 

its true my GLC when fully warmed up reads almost full hot on the factory dash gauge, but when an infared is used its like 175 f... the sender is all the difference

 

It could be an air bubble.