20-08-16, 06:53 PM
I agree with the other comments that it's been overfilled and the excess is getting blown into the air box. If the drain tube is off then it will get sprayed out over the rear of the carbs.
It might not have exhibited the problem while stationary because the gears wouldn't splash the oil about very much at low revs, the oil would be thicker as it's cooler and also it's not getting the extra quantity at the back that it does under acceleration.
What's worrying is that you say the oil level was low. Are you sure about that? It can be very difficult to see… if you've a mate who can lean the bike over to the left while you peer in the window (a torch can help) you will hopefully find the level is very high.
Since you've topped it up yourself it'd be worth double checking that before taking it back to the dealer.
If the level really was low that would indicate excessive blow-by past the piston rings.