Oil pumping from oil tank overflow

[Karcosolutions]

I bought a 1972 CB750K2 today with 14K miles. It has not been started in 8 years but the fuel was drained from the carbs and tank when it was parked. I put fresh gas in and it started on the 3rd kick. Runs great but the oil light is on dim and the overflow from the oil tank is pumping loads of oil. Where do I start to fix this problem?

[Re-run]

First thing to do is download the manual.
Second, what oil is in the bike? Please tell me you at least changed it? I will assume you did.
The oil in the manual is 10-40. If it is thinner than that, it might not be pumping right.