I need some advice guys, I have a random hole in the front of my air box lid beside the two rubber snorkels.
It's it meant to have a pipe/hose/grommet in it?
It's it meant to be left open to draw air?

What happens if it's blocked up?

I’ve never had a standard nc29 with a standard air box but could it be for part 9 in this pic?

https://www.cmsnl.com/honda-cbr400rr-19 ... zJwVBbTWEc

Yup thats the one, it doesn't go anywhere really, i cant see it having any major effect on the performance, looks like its called a sound duct for the JDM bikes so maybe something to do with noise tests in Japan? Thats a stab in the dark though

Its only a very short piece and the end that isn't in the air box doesn't attach to anything else so i wouldn't stress about it