I have looked but cannot find the factory specs for the idle air mixture screw, I know it is running rich, but how much I do not know. It was 5 turns out from closed.

 

Is there a way to tune it?

 

bring it to a shop and get a tune up, sounds like you wouldn't know where to start lol

 

Truck is tuned up. new plugs, wires, cap rotor, air filter fuel filter... everything that I can think of that can affect tuning... I was getting around 15mpg, now about 12mpg. Driving is 60 highway/40city, driven aggressively for the little truck. Nothing rebuilt... any specs? I cannot find them anywhere.

 

lean it out until it idles highest, then make it a little richer

 

Usually, turn the idle mixture screw in until it just bottoms out, the unscrew about 2 1/2 to 3 1/2 turns. Start engine and set the idle speed to around 750-800 rpm. Adjust the mixture screw in/out 1/2 turn to get smooth idle. I usually bump the throttle after each adjustment checking for smooth acceleration off idle.

You can download the FSM here http://www.ncttora.com/fsm/ Scroll down to the 79-85 section. There's a lot of info in this PDF file. Carb adjust is in the fuel section

 

That is not very nice we are a helpful community my man
Would this be a stock carb or a weber carb or asia carb?

 

The factory carb btw.

 

5 turns out sounds extremly rich, any mods? i expect your plugs were looking black, most carbs, you will bottom out the air mixture screw(s) then start at 1 1/2 turns out, if doing by ear, i would do what was mentioned above by lons81. jmo

 

Stock engine, 360k or 460k miles. (Uncle can't remember how many times it rolled over)