Some makes of quads and other vehicles will run without a battery, but not all . It depends on the make and model. Like cars and motorcycles, many newer quads are going all electronic so some of them won't run without the battery. I cannot say whether yours will or not .
I agree but I understand things can get into carb especially on a brand new bike. Im going to let him change the carb and see but if any more problems exist then I will raise cain. I do not want it to become NOT fun for my son.
As long as the battery is fully charged the headlight isn't going to brighten when you rev it up.The voltage readings are right for a charging circuit.