50 oil pump

[<Doug>]

I have a 86 50 Yam. that the previous owner disconnected oil lines to cylinders, routed them back to oil tank and used a premix.I bought new oil line, (clear) and reconnected lines to cylinders, these lines are one piece from pump to cylinders, I know the original system has a black line, a connector, then a length of clear line, the problem is that after I,ve ran motor for even a few hours the oil will drain back down the line to the tank leaving an inch or more of empty line. I know I can't use the oil injection system like this and always premix fuel 100:1, are the check valves bad in oil pump or do I need the original oil line setup on the oil system

[<boats.net>]

The oil pump is probably bad, there is check valves that should go into the oil lines between oil pump and engine but if it is draining back the oil pump is bad and a 86 50HP engine should be 50:1 ratio not 100:1