bogging under acceleration

Hi I am new to this forum and also 2 stroke I just got a 02 Blaster from a friend he said it s bore 40 over stock .and no air box k& n air filter and a full fmf exhaust system. However the quad bogs to the point that you can't ride it once you shift to second gear.he told before he moved that it needs to get jetted but I don't know anything about jetting please help