ok guys, i just installed a weber dfev 32/36 on my 1988 mighty max 2.0. upon installation i installed a electric fuel pump putting out 3.5 psi at about 40gph at the carb with no regulator. i went through all the tuning procedures in the installation papers that came with the carb. i also put a new set of plugs in during installation. i got it running great no stumble or hesitation pulls great through all gears. i drove the truck about 100 miles to school and back and check the plugs. the plugs had a light tan color to the, by my experience they looked just as they should! well after a tank of gas and 190 miles later i seen i was only getting 14 mpg so i checked the plugs again and they are white like its running lean. i checked for vacuum leaks around the carb base and plugged connections with no leaks detected. i have yet to check the timing again but could someone give me some pointers on where to start with this issue? how could it be using so much fuel yet running lean?