Oil check valve
 

It seems that sometimes my engine gets to much oil and is hard to start when I don't start my motor for a couple of weeks, I remember that I changed a one way inline oil check valve somewhere on the motor. My engine is a 150 Mercury 1988 2 stroke oil injection does anyone know any info about that ? Thank you

There is a check valve in the fitting where the hose that pressurizes the oil tank connects to the crankcase.

Thanks Ferm, is it on the port or starboard side? I remember I replace one years ago and it was a easy replacement but I don't remember what side it's on, I think it's on the starboard side but I'm not sure.