Problem with Honda NSR 125

Probelm with Honda NSR 125 hello, am new here and have a big question at once. A friend of mine drives a black Honda NSR 125 with 15 ps. Since the latest the part starts but not more. Do you have some general tips on what this might be about ??? The black box was recently renewed for some reason, spark plug and battery are also new. I have quite a lot of idea of cars but with motorcycles I have to fit. I hope you have tips for me !! THX