Here is a picture of my Hova-Bator 2362n. It has been well used. It has the same thermostat my Sportsman had until we converted it to a digital, so now I have a back-up thermostat. I use it mainly as a hatcher.
Maybe your thermostat is faulty. If you have decreased the thermostat and it still goes to 120 then something might be wrong with the thermostat. I have a 2362n too. No problems with the temp. it does fluctuate a couple of degrees from 99 to 101 but I have had good hatched in it.