White hose near back wheel -- What is it?

"Here are images from a previous answer that you may find useful

The hose could be from the evaporative fuel canister Number 12 and 13 in the second pic . Hope this helps"

I suspect it is a battery overflow hose but not sure. Posting a photo might help confirm it.

"https://www.yamahapartshouse.com/oempart...

The 2007 and the 2008 might be close to the same model. I think that that is the fuel overflow or spillage tube.

best method is to follow it if you can. Might try this trick. put a flashlight in the tube, turn off the lights and see of you can see where the hose reflection is. I've done that a few times to chase down a few hoses on my stuff."