90 HP main bearing oil supply

[whywhyzee]

I'm putting my 1993 90 HP back together. On the block there is what looks to be a lubrication fitting for the main bearing - pic attached. Is it for lubrication? I want to be sure the passage is clean but don't know where it leads and can't blow air or cleaner through it. Any insight? Thanks.

 

[racerone]

It is a big $$ check valve.----It is part of oil recirculation system..----Just replaced one on a 1993 V-4 rebuild this spring.

 

[Dave1027]

Since it's a check valve, shouldn't he be able to blow through it from one direction?

 

[Faztbullet]

but don't know where it leads and can't blow air or cleaner through it. Any insight?

look it the bottom of cylinder..