gear box hose to nowhere......

I need assistance please.
Last week I worked on replacing my "blow by hoses". Had to move the tank and take the battery box out etc. This is a replacement tank I lined with expoxy and had installed by MPH Cycles in Houston because I was a newbie to the bike and maybe wasn't even signed up here yet. So, this is the first time the tank has been taken off and the battery box out. When I removed the battery box I found this lose hose just laying in there (pictured), which has obviously been that way for 7 years. It appears to be part number AP8101595 and it's called a "fuel hose". It runs into the top of the gear box. I can't see what it's supposed to be connected to (even after looking at the parts manual). Now I did do a canisterectomy years ago but I don't remember this being part of that and it's behind the battery box, that I never had that out its been that way for a very long time. I also found a pinched fuel overflow drain line that I rerouted so it wasn't laying under the battery.
Can someone tell me if I should just let this line "breathe" or plug it? There is no markings on the end of it as you can see that show it was clamped to anything.
As always, many thanks!

John



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Did some more searching and reading here. It appears to be the gearbox breather........but it seems odd to just hang out and breathe........I still need a sanity check.

Correct. It's routed atop the battery box from top of gearbox. Connects to nothing just allowed to breath in a "dry" area. Routing is correct. At least that's how mine has always been after canister removal.

Yep, I was just looking at that hose yesterday when I cleaned out the airbox. I put it right back where I found it!

Yup, that's where it sits.

It's only purpose is to allow the air in the gearbox to expand and vent to atmosphere rather than pressurising the gearbox. The old Tonti framed bikes had a similar set up. The V11 series used an identical 'Top hat' breather to that fitted to the CARC bevelbox. Unfortunately it was directly in line with the throw off spray from the rear wheel in the wet and was utterly unprotected resulting in a gearbox full of water if you rode in the rain!

Obviously the engineers made a note of that and when the gearbox was redesigned for the CARC bikes the breather nipple was moved off centre and refitted with a hose. It must work as you don't get water in a Nuovo six speed.

Thanks to all the replies…