hello i'm in need of some help, ive been trying to get information on my xr2i for the past 5 months hitting brick walls everytime

anyways heres how it goes i fill up about half a tank of petrol and it will last about 2 days doing about 40 miles now i don't know about you guys but that is like insanely stupid lol, i was then told that xr2i were recalled back in there days not entirely sure why though but i think it was something to do with idling, i have the model where the idle air control valve goes into the back of the airbox but unfortunately i dont have the airbox and hit a brick wall everytime trying to locate one can anyone please help me because its stress me out and my wallet on petrol i can supply as much information as possible i kind of know a bit about motors to a certain degree kind regards