my sons btm 49cc scooter starts but cuts out when you open throtle up whats causing it to do that

paul, October 2012

either a blocked jet (main jet) in the carb ,no fuel or water in the fuel
also check the valve clearances as these suffer from the clearances closing up
and make sure the air filter is on properly and has no leaks a these bikes run very weak fuel/air mixture from new.

adam bike doctor(of milton keynes motorcycle centre), October 2012