Hello guys, I have taken over the old Honda CBR 600f Bj.89/90 PC23 from a friend who has not driven it for many years. I had to find out now unfortunately that it starts to stutter at 80km/h and becomes slower, until it finally remains lying, if I do not go off the gas. In the city traffic, i.e. up to 80km/h, it drives without problems. The problem exists permanently and occurs even with almost empty tank earlier, say already from 75km/h. When the Choke is pulled, I can also drive 100km/h without any problems. The fuel supply is definitely OK, the carburettors I have cleaned myself thoroughly and the candles are new. However, the candles are white, i.e. too thin mixture. If I put the mixture fatter, I feel no difference. To the stuttering: So I speed up to about 80km/h and if I turn further at the gas handle, it stops accelerating, stutters and gets slower. I can now continue turning at the gas handle, but without reaction, I’m just about to hit the gas. Here she accelerates a little bit, but also starts stuttering again. I have no idea what else it might be. Please for your help, thank you.