I had my Vitality 50 4T in for the 3000Km maintenance. Before the maintenance I could get 55km/hr (35mph approx) on the flat, but since I can't get more than 40Km/hr (25mph approx) on the flat. The mechanic says there is nothing wrong with the scooter and that is the way it is supposed to run. He has had it for a month and claims he can not get it any better, personally I don't think he even looked at it since. He still maintains that the scooter runs perfectly. Anyone got any suggestions?