Motorcycle Questions? Ask a Mechanic.
Hi and thank you for your question.
This is a serious issue that needs to be resolved before you attempt to ride the bike. This has 2 likely culprits. It is either an oil pump problem, where the oil pump is not pumping, or you have clogged oil passages. I would start out by removing the oil pump and inspecting it. You are looking for any signs of damage. Things like a sheared pin that is supposed to spin the inner rotor of the oil pump, also inspect the mating surfaces of the inner and outer rotors of the oil pump for any signs of scratching or scoring. If they are not perfectly smooth with a mirror finish, they need to be replaced. They are very dependent on tight tolerances to be efficient an move oil.
You will need to trace the oil passages starting at the oil pump working their way through the engine to ensure there is no restriction. You should use a combination of contact cleaner and compressed air should resolve any issues there.
I would also give a quick look at the cams right now to make sure they have not starved for oil and gotten damaged.
If you have any more questions feel free to ask.