mercruiser alpha 1 gen 2 oil passage

[wolfdog1947]

what is the trick to make the oil passage between upper and lower unti seal properly?

 

[RicardoMarine]

Clean mating surfaces, no warpage, and a new gasket/O-ring each time disassembled.
You should be able to catch this during your "dry" pressure/vacuum Leak-Down test!

 

[bondo]

what is the trick to make the oil passage between upper and lower unti seal properly?

Ayuh,.... Like Rick said, by using a New quad-ring every time it's apart....