RE: Servo Burnout
6.0V direct is OK. Obviously return the servo, I don't think it should have burned out. The one "exception" to that might be if you're using a strong spring as an automatic throttle return (some gas-engine carbs have these springs installed). We highly recommend removing those strong springs (note I am not talking about the lightweight springs found in most hobby glow engines, I'm only talking about the very strong springs sometimes found on the gas engines).