This hose fell out from above my subframe while I was replacing it. I haven't figured out where it goes yet, but I've ridden a good 20 miles without it. Just curious where it goes, and how important it really is.

I'm thinking it's numbers 1, and 2.
OEM Parts Polaris HAWKEYE 2X4/4X4 (A06LB27AA) 2006 ENGINE MOUNTING - A06LB27AA/LD27AA/AB/AC/AD - Cheap Cycle Parts

Any help is appreciated

 

it is a one check valve for a vent line.

 

I would say it goes on the bottom of your carb float bowl as an overflow line, mine looks the same.