Pnut Butter

this is on a chironex spartan 500. cfmoto 500 engine. i have searched but i cannot find anything on that hose. 

thx

does anyone know what/where this hose get connected to. is it a vacuum or vent... engine run but when given throttle it tends to bog or die out. if i blow a steady stream of air in it engine throttle responds perfect. 

Hi Everyone