Had new hitachi 2 bbl carb put on 1987 subaru gl. Idles and runs good.But now MPG went down and there is a slight smell of gas when i shut it off.Is it a fuel/air problem or what? Can i adjust it myself or do i need my mechanic to do it? Thanks

yeah that sounds like it could just be a mixture problem, there is a mixture screw somewhere on those carbs but im not exactly sure where... could be a number of other things though, make sure all your vacuum lines are hooked up and not leaking, make sure your choke isnt sticking in the on position or partially on position as well. just some thoughts, i had the same issue on my dodge d50, turned out the butterfly was a little too big and would stick closed sometimes.