I think you have two different problems
1. Your needle and seat in the carb is leaking.
2. The reed valve under the breather tube coming from the valve lifter is bad.
On all my 782s I install a fuel shut off valve just before the fuel pump. If you don't shut off the fuel all the fuel will fill up your engine crankcase with gas.
If the reed valve is bad your engine builds up internal crankcase pressure and will
blow oil out the breather tube.
Brian
