scoutcollector

I have my first Dodge truck. Just bought it, have no backstory on the vehicle. It's an 86 D350 dually panel truck, has a 360 engine, 4 barrel Rochester Quadrajet, 4 speed manual transmission. Motor starts up fine but engine is running super rich. Very strong unburnt fuel smell from exhaust. I would like to start a simple tune up process. Part of that process I was going to tune the air fuel on the carb but the air fuel mixture screws on this carb are not there. Instead, it looks like they are plugged. I've never seen this before. Attatched picture of where the screws should be. Has anyone else ever seen this? Or do you think that this might be a carb that was reconditioned by some shop and then blocked off. I've never heard of this before.

Hopefully the picture uploaded the correct way. If it didn't, sorry for the problem. If you look at the picture, instead of a screw it has those weird indentations that don't look like they're meant to turn, on both sides of the carb where mixture screws would be.

scoutcollector

I did some more late night googling about those plugs and discovered there called welch plugs, they were put in there so people would not be able to mess with emissions, Now I just have to learn a good method of removal with out killing my carb base. If any one has done this , advise would be helpful.

Kuvasz101

Yes I've seen this before. Those are expansion type plugs/caps. You have to use a small drill going slowly and make a hole where you can stick a pick or small screwdriver in and pop it out. That being said, I doubt that's why it's running rich. A basic tune-up to start and check float settings. If I recall, Youtube had a video on popping them out.

RacerHog

Get those Idle air mixture screw plugs out of the way......
Also Make sure the choke is not stuck closed or partly closed...
Look down the air horn and make sure it is not dribbling fuel....

Stevem

These carbs of this age are known for the float to go bad, get soggy with fuel and then ride low enough for the needle to stay open and make for a high fuel level which will be seen as fuel dribbling out of the booster even at idle.
get a brass float along with the rebuilt kit.

once the carb is apart check to see how much Play there is in the primary throttle shaft.
the carb body wares a lot and makes for a vacuum leak which allows more fuel in then needed.
Throttle shaft bushing kits and the special drill bit needed to install them can be had in kits so you can do this job yourself.

if the motor is in good condition and you have no vacuum leaks and the stock exh system is on the truck then there should be no need to yank out those pressed in plugs to access the mixture screws, in fact your rich condition you have taking place now could be due to old dry rotted vacuum hoses, so go over all of these carefully.
Also many times the power piston that the primary metering rods hang on gets gummed up and stuck in a up position which will make for rich running .
this condition you will not see until you pop the air horn off.

the last and most important check after you rebuild the carb before you bolt it back on is to turn it upside down and blow into the fuel inlet with your mouth.
if you hear air entering the carb then the needle is hanging up and the motor will flood out within 10 seconds of the motor starting up.
you do not want to kill a good motor fast by washing out the rings!

scoutcollector

Thanks for all the help. It will be a few weeks before I can start in on the truck, but at least I have a solid attack plan now.