Yam blu

Also sorry for not posting an intro in the new members section I'm posting on for the other half who will do that herself Didn't want 2 piss any1 off Cheers

I own a ybr 125 with just over 4000 on the clock Don't have a clue about engines so would be grateful for any advice Some 1 tried to steal my bike and a cowboy fixed the cdi unit and ignition set Now when I open up above 50 it splutters,jerks and hardly touches 60 Some 1 said it might be the carb? Any input would be great