Adjusting the thermostat for best temperature

I am not fimiliar with that brand . the corn/oil ratio is 3 to 1 so if you add 1-1/2 cups (12oz.) of corn with 4 oz. of oil the popping cycle from the time you dump the corn and oil in to when you dump it shoul be around 3-1/2 min. if its much longer its too much so try 8 oz of corn and 2-1/2 oz. of oil. By you using this test or formula I am assuming the kettle thermostat is set correctly already.

do you put a half a teaspoon of oil in first before the corn kernels
other than that have the unit checked by an electrical appliance shop for problem thermostat or heating element

Not enough heat in the kettle to do the job. The corn will dry out and pop poorly when there is not enough heat. Either a thermostat adjustment or replacement or a bad element.

wait longer between batches

Generally, you want 3 oz. of corn to one 1oz of oil. The amount of corn you can put in the kettle depends on the size of the kettle. So take the kettle size, (I think that machine is an 8 oz popper) and divide 8 by three to get 2.66 oz. (about a third of a cup) of oil needed. So you would use 1 cup of corn, and a third cup of oil.

Make sure your agitator arms are properly functioning. If the corn is not being properly stirred, it will not pop. Also, make sure you are using the correct type of popcorn oil.

There are several possible culprits for your Kernel Caper.
1) You may need to add a little more oil to the kettle. Let it come to full heat--just as soon as the oil starts to smoke.
2) The corn you are using must be reasonable fresh and have sufficient moisture to pop the kernel. You can try putting 1 tsp/1 lb of corn in a ziploc bag or screw top bottle. Leave for 24 to 48 hrs to let the corn absorb the moisture.
3) Finally, due to the small size of the popping kettle some kernels will be thrown from the kettle from other kernels popping open.
This is a great little popper. You might have some luck decreasing the size of your batch--reduce your oil and corn by 1/4 each.
Good Luck

http://www.concessionpalace.com/concession-tutorials/P-60_60_Special_Uncle_Walts-1866_2085_2086_2656-popcorn-machines.pdf

this happens if you put took much in at a time

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