So my 99 Dr350se got a new noise the other day and hoping someone else may have had a similar issue
at around 4900-5200 rpm there is a buzzing like grindiing sound coming from the left side of the bike. I think we have narrowed it down to the crankcase.
It happens regardless of speed or gear that I am in. It also seems to happen more often as it decellerates but it does happen on the way up sometimes too.
Oil is good and nothing is obviously loose that i have found yet. Chain has also recently been lubed.
Any help is appreciated