Place the turkey in the frying basket and lower into the deep fryer. Pour in enough water to cover the turkey by 1 inch; if a maximum fill line is labeled on the machine, the amount should fall below the line (if it doesnt, your turkeys too big for the fryer!). Remove the turkey, letting the excess water drip into the fryer, then measure the distance between the water level and the top of the fryer. Discard the water and pat the turkey completely dry.
Dry the deep fryer and basket. Fill the fryer with the oil to the measured water line, close the lid and preheat to 375 degrees . Season the turkey with salt and pepper. (Inject and rub the turkey with seasonings, if using.)
When the oil is ready, generously oil the fryer basket and place the turkey inside breast side up. Wearing long, heavy-duty protective gloves or mitts, use a hook, wooden broomstick handle or sturdy wooden spoon handle to very slowly lower the turkey into the hot oil. Close the lid.
Fry the turkey, undisturbed, for 45 minutes. (Do not leave the turkey unattended.) Slowly and carefully lift the basket out of the oil, letting the excess oil drip off; the turkey temperature should register 165 degrees on an instant-read thermometer inserted in the inner thigh. If the temperature falls short, continue to fry the bird, checking the temperature every 10 minutes.
Carefully remove the fryer basket from the deep fryer and drain on a paper-towel-lined baking sheet. When cool enough to handle, about 10 minutes, roll the turkey out of the basket and onto a cutting board. Tent loosely with foil for 30 minutes before carving.