Hello, My scooter drives at once only 20 kmh (previously 60 kmh) after the problem has occurred, I have installed a new carburetor, suction nozzle, air filter and spark plug. As far as so good, but the problem persists. To my scooter: Mbk Booster Rocket 4Va bj 96 with manual choke. Starting it does quite normal. I slowly do not know any more! Greetings