Bad gas Mileage

I have an 88 D50, carb 2.6. I just bought it a couple weeks ago and gave it a tune up, new plugs, wires, dist, Air filter, oil, etc. Now i noticed today that its getting bad gas mileage, we're talkin maybe 10 MPG. I think my carb needs adjusted because it stalls out on takeoff, but could this cause such bad gas mileage? 02 censor perhapse?