Gilera runner 50sp 06 (New shape) keeps bogging out when acc

My gilera runner 50 keeps boggin out (hesitating) when pulling away there is no water in the carb and the air filter is clean also i have changed the spark plug, the ped also seems to not electric start when cold (the battery is fine) and starts on 2nd kick, runs fine and only plays up when slowing down to a stop for example a turnin the when you go to acclerate it boggs and i end up fallin over the bars lol
Can anyone help ??????