Hello I have a 39s popcorn machine . I have power kettle spins but not get hot . anything I can do ?

either bad / shorted switch or element

Order a new switch from Gold Medal. The number is 42532

There are many possible problems that will cause your agitator to not spin, But you said the gear in the cabinet comes off easily, it should not.
There is a flat part of the motor shaft that extends thru the top of the cabinet that the gear should be tightened onto with an allen wrench via a set screw. This is the first place to check. When the motor is on, you should not be able to stop that cabinet gear from turning. (not easily anyway).

Unplug the kettle and check voltage at the kettle reciprocal . If correct voltage is there with the kettle switch on put a ohm meter across the hot and neutral terminals of the kettle plug . If there is no continuity between them either a wire burned off in the kettle or the thermostat is bad. When they go out its usually open so no power will go thru it.

The thermostat built into the kettle stops the kettle from heating at a prescribed temperature. usually around 425 F. This is hot enough to smoke and cause instant burns, but is the required temp for popping popcorn.

I do not know of a "thermal fuse" built into popcorn machines. Mechanical thermo stats are not flawless. they can and do malfunction, either too cold or too hot. the model popper you have is not adjustable, or repairable.

If you are tripping a electrical circuit breaker that is a different problem not related to kettle heat. It is a symptom of an overloading problem of your outlet, or a ground fault in the popcorn popper.

are you using a few drops of cooling oil to pop the corn

I have a Popcorn machine from Nostalgia too that had this problem. I cleaned it out and everything but it still had the problem of the it getting stuck. After days of analizing, I found the solution. after a while the ceiling of the popcorn machine starts to fall in, lowering the handles of where the kettle goes. making the knob that turns being lower that the one that makes it turn, causing it to get stuck, all I did is add so leverage so the kettle is once again at the same level or higher. Making it turn with greater force and not getting stuck. In other words make sure the turning mechanism is leveled and not one lower than the other. preferably the kettle part being higher.

Ok, well most thing with an element are pretty easy to troubleshoot, you need to check, there is Power to the Element, Check for any "Thermal Fuses" Check wiring to Element, essentially , at where they wires join to the elements ends. Check the Element, it should have some resistance, anything from 7 14 OHMS would be OK, usually elements fail, open circuit. Check Thermostat too, see if it is opening and closing at the desired temperature. The thermostat and brain are the only things that can stop things.

Normally that is caused by too many kernels used. It pops too fast and jams up in the kettle. It could be a problem with the kettle though. Call 920-347-9122 for help with it.

When Popper Has Popped Corn Just Before.
1. Pour the properly measure amount of Oil into the kettle.
2. Wait about 45 seconds - or until the Oil in the kettle starts to smoke slightly.
3. Pour the contents of the properly measured corn cup (kernels plus popcorn salt or Flavacol) into the kettle.
4. Wait about 2 1/2 minutes. If you are using a pan on the stove without an agitator, you must constantly shake gently. When the crackling noise of the popping corn is no longer heard, dump the kettle and empty it completely.
5. Repeat if needed for more popcorn.
6. When you are finished popping, turn off the kettle agitator switch (if you have one) and turn off the Pilot light/ heat switch.
7. After the machine has cooled enough so as not to be dangerously hot, wipe the outside of the kettle with a soft damp cloth. This helps prevent a heavy build-up of the Oil.

TIPS
- Bagged floss keeps a day or two, depending on the humidity
- Use bags to make and display cotton candy in advance - use cones for immediate sales
- Unless you're experienced, it's best to turn off the motor to refill the spinner head
- If machine will be used more than 20ft. from power source, be sure to have an adequate extension cord