Lower end cap... check valve??

[Grumpy Bear]

'74 Merc 500 Thunderbolt. I noticed this hole when I took off the lower end cap -- nothing in it and light and air blows right through. Then I see on some diagram that there is supposed to be a tiny check valve in there?? What is the purpose of that? Is there supposed to be a check valve in there? And how do you install it? Thanks!

 

[Grumpy Bear]

Huh... turns out my motor serial number doesn't fall into those motors that use this part in the US. Thanks, Racerone, for your insight!