Im getting black soot out of the tailpipe and the truck is still running like crap with the carb cleaned out and new everything else ignition wise.

I need to lean the carb out, can anyone help me discover where gas and air mixture screws are.

Also is there any kind of factory baseline? You know like both all the way in and them back them both out 2 turns?

Thanks.

 

Seafoam. People's methods vary but here's mine:

Run the truck till the motor is fully warm.
While running, slowly pour half the can into the carb while feathering the gas so it doesn't stall.
Unhook the brake booster hose on the booster end and put the rest of the Seafoam through there.
Shut off the engine and let it sit for an hour.
Fire it up and go beat the bag out of it till it stops smoking!

Now you can just attack the outside of the carb with carb cleaner to make sure all the linkage is nice and clean.

That worked wonders for me. I've literally done it on every car and truck I've owned... even my motorcyles, garden tractor, you name it! Stuff is magical.

As for adjusting? Dunno but I'd leave it alone till you clean it well.

 

Do you have an oxygen sensor hooked up? Are all of your vacuum lines hooked up properly? It could be about anything as I don't believe your carb has an air/fuel adjustment, but if it did it would be a screw on the bottom front of the carb.

 

Well I have no idea if the guy before me hooked all the vac lines up correctly.

However, I did find the adjuster screws on the base of the carb took them in all the way and then out two turns.

Darn thing is still running too rich.

I am going to check the vac lines one more time, I see that the EGR valve isnt even hooked to anything. I think I'll try the seafoam trick too, at this point why not....

 

You might try
What you want to do is set the mixture screws out about 2 turns just to get it to idle. Then put the vacuum gauge on a full "manifold" vacuum port on the carb and adjust the idle mixture screws until you get maximum vacuum at idle. Readjust idle as desired.

 

I took a shot at rebuilding my carborator recently and found this exploded view of the parts on the internet. The Part 51 is the 'Idle Adjusting screw' (air to Fuel mixture screw?). Mine were out 2.25 turns when I took it apart so that is where I put them back to. I don't have a vacuum guage but heard that you can, at idle, adjust them in and out until you hear the engine bog down and set half between these two points as a start. I didn't have much luck at trying this so I just put them where they were before, I ran them all the way in and backed them out 2.25 turns.

They take a 3/32 allen wrench. If the cap, part 52, is there. the rebuild kit said to put a #8 screw into it and hold the cap while turning the screw to get the cap to back out. The caps weren't there on mine when I took it apart.

http://www.carburetorfactory.com/expvw16.html

The vacuum lines were shown on a diagram sticker inside the engine compartment on the driver's side wall on my W150. The diagram showed where the all went to, you could use this to check if they are going the right places. I have found this pretty difficult though, to track them around the engine.

 

Yeah I found that same diagram, and I adjusted my screws back to 2 turns out. My issue was all that sediment in the bottom of the bowl. I cleaned the carb and reassembled it then when it was still running like crap I just replaced my fouled plugs. ( the plugs fouled out between me installing them and then cleaning the carb )

 

If you have messed with adjusting the carb but put it back to the factory settings try this. The seafoam trick works. If you want to get it alittle cleaner. Try to purchase a ( 2 step fuel intake cleaner ) Smart Blend makes a good product for this. The part number is 17025-K and also change out the plugs with platinum Plugs. People have mixed feelings about these plugs but they will help get a CLEAN spark. Clean spark and a clean intake will give you a clean burn.
ALSO. Try and loosen up your distributor. and and turn it alittle back and fourth. The idle will get stronger or more retarded. Find the sweet spot and adjust you curb idle.
This is a 2bbl carb. Adjusting the mixture to much looking for that 4bbl carb sound is NOT going to happen. Dont get it to lean or you will heat up the piston to much. Its an older car/truck it will smell old. Carb engine smell is stronger than throttle body.
Good Luck