HJ1259 - User Documentation New Guides

Hi I have a gilera gp800 2009 model, recently i realise it stalls or hesitates during acceleration, usually it happens during some few minutes before I begin a ride. Most times when the engine is yet to attain the working temperature. However for onward acceleration it does not hesitate nor stall. I have done the best to keep my fuel with the right quality, also i add some bit of injector cleaner and fuel cleaner, but i amazed why it still stalls. What could be causing this?