Do you have a fan? What is your incubator? Does it have a thermostat? How often have you been adjusting it? Are you checking the temp in all areas of the bator? Is your thermometer calibrated? How did you calibrate it? What kind is it? What day are they on? What did last candle show? Sorry if I'm bombarding you with questions. I haven't been following your hatching details. That's definitely too much of a temp change. If you get a hatch at all, with those numbers, you're likely to have some developmental abnormalities. If I had to guess, I'd say that your thermostat is bad.