Flickering oil light 990 Super Duke
I don't know whether this helps but I've had a similar problem with noisy top end on start up, oil light after take off and after 3-4 minutes reducing to a flickering and then off. I took the bike to a very experienced KTM mechanic and after removing the oil filter which showed the deformed section similar to examples of failed water pumps, but no sign of cooland in the oil. The oil filter (put in by PO) was not a KTM oil filter. The mechanic says he's seen this happen a number of time with non OEM filters, including K&N. OEM filter is in, no oil light on and I ride home. I should add that the OEM oil filter has the part no on the top of the filter, mine had nothing.
The Myth of Sisyphus