Just had my first service at about 800km. No charge. Generally things are fine but since new the bike has had a very annoying resonant booming noise starting at 4000 rpm and lasting till 5000rpm. Well, wind noise probably drowns out everything thereafter. Comfortably quiet below 4000rpm. Didn't notice this problem when I had a ride on the demo bike. Had hoped the service might improve things, but no. Asked mechanic to check silencer and engine mountings but to no effect. Anyone any suggestions other than earplugs. Dealer suggested changing helmet!