Since the motor is oiling on 2 cylinders only, my inclination would be to suspect either valve guide seals for those cylinders or maybe a breach in the intake gasket(s), allowing oily vapor from the crankcase to be drawn into those 2 cylinders when their intake valves are open. Either problem is not going to fix itself. I'm not telling you what to do, but if it were my motor, I'd be gettin' my tools out. Wait and let some of the others on this forum chime in, maybe someone has a better idea.

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