Its a 1986 Yamaha 8 hp.
Can it possibly be a connection to sync it with another motor? The motor did have a clamp on it when I got it, I think that connected it with another motor to steer them both at the same time. But then again, I don't know how the throttles would be sync'd together.
Is it maybe used for running lights, maybe charge a battery like an alternator?
I can't test it because my hose is frozen, gotta wait until spring to start it.