Whistleing sound when cruising at 4000rpm
Hey guys, I'm new to this forum and just got a second hand 899. Is it normal for the bike to make a high pitch whistleing sound when cruising at around 4000rpm? Makes Street riding tough without ear plugs. If I hang off either side of the bike I do not hear it. Is it coming from the airbox? Some plastic bits not on right? The bike has 20000 km.