I have a neighbor kid that just bought a AD-11 Johnson it runs pretty good but is leaking oil out of the top main, the crank is tight but the slinger is leaking, where can I find a slinger or can it be converted to take a seal?
Most Johnsons that vintage have a carbon seal with an O-ring in it. The O-ring dries out and cracks with age. If the carbon seal is OK (not broken) get a replacement O-ring.
I know it isn't a trick question--I just now saw it. As you know, there is no seal, only a slinger. Any oil that escapes the bearing is thrown off by the slinger and then is sucked back down into the intake manifold via oil passages in the crankcase. You can remove the intake manifold and blow the passage out with compressed air if you think it is clogged. But it probably isn't.
It is such a simple system that it is almost crazy--but it works just fine on many thousands of motors.
The one thing that defeats it is worn out main bearings with so much clearance that the oil blows out in large amounts and overwhelms the return path. When that happens, the powerhead is worn out beyond practical repair.
