SAE 10W-30 synthetic motor oil, wet-clutch approved,
API GL-1, qty: one liter
This what the manufacturer calls out for in the service manual
I put in what I had on hand. If the leak is stopped and I don't have to pull the motor again I will drain and fill with the required oil.
I honestly don't believe that the seal was leaking, I only changed it because I had already ordered it before I realized that the oil is actually coming from that key way.
The bike is still not leaking and it has been on the side stand for a week.
Cheers