Hi guys, I'm new to riding and I got myself a used honda cbr 250rr replica. It was going just fine until yesterday. I went to the gas station and when I got into 3rd gear I heard some choking sound from the exhaust. So I got on the highway to check will it happen at higher speed and it did, more than once, it makes me shift to the next gear when I don't use the whole potential of the current one. And I don't know if it has some speed limiter or something but it can't go faster than 95km/h. But now when this started to happen it can't go over 80km/h without the popping sound. What could it be?