Vent hose from aftermarket gas cap goes where?

[stopintime]

Directly under the cap, there's a hole with a thin vent hose.

Where does it go?

[uglyducky]

just like it is 

[stopintime]

just like it is 

I'm asking about the other, loose, end - the one that seems to be designed to go into an excisting hole in the tank assembly.

[ducpainter]

Directly under the cap, there's a hole with a thin vent hose.

Where does it go?

I'd attach it to the vent tube in the tank.

Are you using a steel or plastic tank?

[stopintime]

I'd attach it to the vent tube in the tank.

Are you using a steel or plastic tank?

Plastic tank. AFAIK there are two places it can go (maybe more) - one vertical at about 6 o'clock and one horizontal at 9 o'clock. 9 o'clock is probably overflow....

[ducpainter]

Plastic tank. AFAIK there are two places it can go (maybe more) - one vertical at about 6 o'clock and one horizontal at 9 o'clock. 9 o'clock is probably overflow....

If you have eliminated the canister it doesn't really matter which one you use.

The unused tube will need to be plugged.

[stopintime]

Euro bike - no cannister.

I see two (overflow?) holes in the filler neck. There are two rubber hoses going out of the tank - both ending in the hose which is dripping gas when I overfill. I'm guessing they ae not relevant here.

There is a threaded hole, brass insert, at 8 0'clock. Don't know what that's for.

Then there's the black thingy at 6 o'clock, which I assume is letting air into the tank? To avoid vacum?
If this is correct, I'm wondering why there's a vent tube on the gas cap. Maybe it's not a vent tube - maybe it's another overflow tube?

[ducpainter]

On a US bike the tube from that black thing is the vent which goes to the canister. It aligns with a small hole in the stock cap.

The other is the cap area drain which prevents water from building up under the cap and getting into the tank and allows the depression to drain if you overfill.

That A/M cap wont vent properly without that tube connected to atmosphere.

If you have a leak when you fill one of those rubber hoses might have a split.

You should pull the pump and check things from the bottom. You can't really see from the top.