Oil injection tank

[reloader51]

I have a 2004 Mercury 115 2 stroke with oil injection tank on motor. There is a rubber plug on top of the oil tank. Should it be open or closed during operation? Thanks!!

 

[fitz73222]

That should be a vent and open

 

[reloader51]

Thank you. Any idea when it would need to be closed?

 

[R_P]

Serial number? Look up the parts diagram of your engine and see what part you are referring to in the oil tank diagram

 

[reloader51]

19299A1