Anyone can tell me?

[Bob Allums]

I am a newby to this Forum, I have an older 70 Yamaha motor and it has a hole in the top front left part of the cowling with a plate with a rubber seal sometimes holding it in place.

What is that Hole for and why did they put it there?

I have seen it in other pics, so previous owner didn't cut it there.

[rodbolt17]

used to be for filling the oil tank without removing the hood.