Carb seems level, have 'tapped' carb, bounced bike a few times, but as soon as tap is on, it p*** itself. So will go clean carb. But I did notice that the drain spout 'bulge' on the bottom of the carb, seems to be slowly hammering through the gearbox casing, as it vibrates! Is this 'normal'? Maybe I'll araldite a small metal plate under it, or wedge a bit of inner tube?