hi there can someone help me i have a yz80 and i have just rebilt it an there is a hose that comes from the air box or reed valve and i dont no where it goes can so some help and see if u hold yor finger over the hose the bike will start and when u take your finger off it cts ot does anyone know wat its for ?? gary

it most likely goes to a 'boost bottle' Gary ?

wat do u mean m8 wats a boost bottle ????

its a closed chamber connected to the inlet, you need to post a photo and state the year of the bike...not enough info i'm afraid, and i'm just guessing because of that