Stretch111967

i have 1 1985 Subaru GL 4cylnder,4 wheel drive. i got the rpms at idle going about 2500 rpms.so when i start driving down the road it has no power ,it backfires and barely go 5 mph.how do i set the timing,and does the carb have only 1 idle screw? and also does the carb have a fuel /air mixture screw and if so how to set that one? i tryed to turn screw on front of carb and it does nothing. i think also i am leaking oil under front of car pretty good,it might need front seal replaced. i replaced spark plugs,wires,rotor,cap,oil filter.please help!! thks