My US60 has digital servos all around and I got around 3 to 4 flights on my 1400mAh nicad battery before reaching 9.6 volts. I've recently put a 2700mAh nickel metal battery in and fly all day. The Saito 100 is a great engine. Easy to start and maintain. Just follow Saito's break in instructions and you'll be good to go.