Hey everybody. I'm a new member here. Nice forum by the way. Anywho, I'm Adam. I just picked up a 1981 F-150 Custom with the 300 cid I-6. Here is my question. The carbuerator on it is running WAY too rich. However, it looks nothing like the carbuerators in the manual. I'm not too knowledgeable when it comes to carbs, so I can't find the damn mixture adjustment. There is a sticker on the carb that says manf. by carter for motorcraft. Is this a stock carb? If not, anybody know anything about this carb? It's the first of a few problems I'm having with the truck. Any input would be greatly appreciated. I'll post up some pics in a little while. I have to find my camera.

 

Here she is in all her glory. I call her Betsy. I picked this thing up from a lady for $200. It was her husbands and he passed away about a year ago. It's been sitting ever since. It has less than 90000 miles on it and it drove it home. What do you think? Damn, nevermind. How do you post pics?

Let's see if this works. https://www.ford-trucks.com/user_gal...&albumid=17152

 

Nice looking truck. sounds like it may be more than your mixture screwq. that only effects the mixture at an idle. you may have a sunken float. look for a tag on the carb or a number stanped or cast into the base of the carb. good luck

 

You STOLE that truck!!!!

 

That truck is a baby-doll. We all hate you. Welcome to the forum.

You can rebuild that carb pretty easily, or have someone else do it if you are challenged in the carb department.

Your 81 came with a Carter YF 1bbl carb. The 300 six is the most dependable engine Ford built.

 

Howdy,

Yes, that is the stock carb. It should have a tag on the front that has the motorcraft part number and suffex code. It would help discover the exact one you have cause the YF or YFA carb has many different calibrations.

Here's a few questions, Is it the feedback carb, or the non-feedback carb? If it's a feedback carb it will have a solonoid on the left hand side with two wires going out of it. (not the throttle position sol for the air conditioner on the right side if equipped).

If it is a feedback carb, make sure the feedback solonoid is operating. It should make (tic, tic, tic) noises in rappid progression when working with the ignition on. If that seems to be working (if applicable, or don't have a feedback carb) try, the mixture adjustment screw. If the carb is original it will have a tamper proof cap on it that will have to be drilled off to get to the screw. The mixture screw is located on the right side of the carb in the throttle body just below a vaccume port for the EGR/vaccume advance etc.. (depends on model) or just above where the spacer bolts up to the carb.

hope this helps...

 

Carb kit time. I just did my first one on a similar YFA carb. I've been around cars since I was a kid, but never tackled carbs. If you can change plugs, fuel filter and distributor cap/rotor, that kinda stuff, you could probably handle it alright. Clean it well, keep it clean and read the directions that come with the kit, then ask here if you have any questions or problems. You'll perhaps need some "star" drivers if the screws are not standard philips crosspoint.

I don't think your carb has any feedback systems to worry about. Despite differences, these Carter YF's and YFA's are all quite similar internally and very simple designs, as carbs go. I probably have the match to yours on my bench right now. Haynes manuals don't show anything on the carbs, Chilton may be better. My Chilton Jeep manual has some great tune-up info and views of the Carters and others. The carb kit will have a good exploded view to work with.

There's some loose parts that can fall out if you just flip it over once it's apart, so watch for that. I still forgot a couple times, but found them all, even in the sawdust and grit!

Of course, with the price you paid, you could afford to have it professionally rebuilt or upgrade to a new carb and intake and still be a couple grand or more to the good. Nice score!

-Ed

 

Nice! I bet every one here would give you $400, so as to double your money. Just kidding. Good deal, and looks to be a CA truck.

As said before, it may be internal, because it sat for a couple years, but do the basics first. Idle adjustment. Make sure choke is opening completely.

Feedback probably because it CA truck. Feedback solenoid quick check: Increase rpms to 1500, unplug, truck should increase a few rpms, plug it back in, and rpms should decrease. All done with truck warmed up.

Good Luck. And yes I am as jealous as everyone else. Don't find many deals like that.

 

Had a problem like that with my '84 F150. Evntually reached the point where the carb would flood the engine and kill it. Beat my head against the wall for a few days then checked the carb float. It's been running great ever since.

 

Thanks for the help everybody. I'll check it all out as soon as I get another day off. Anywho, yeah, it runs rich as hell. It also has A LOT of blow-by. I know, I know, I either need to have my head rebuilt, or just buy a new one (remanufactured anyway). It's actually cheaper to buy the new one than it is to have the existing rebuilt. I hear the valve guides on these go rather quickly. Even in it's current state, it towed my boat with minimal hassle. What a friggin awesome truck. I was never a fan of Fords at all till I got my Thunderbird. It's a 93 and runs like a champ. Then I got this truck, and it's still solid as hell. No rattles in the interior, suspension is rock solid, and the motor, despite it's problems, is still strong. I can't wait to have this thing running properly. Thanks again for all the advice, I'll check it all out next weekend probably.

 

Dont assume that having blow-by means you need to rebuild anything. Check out and clean the entire PCV system. By this, I mean clean the valve, hose, and fitting into the manifold. Here at this fitting things can easily be clogged up. You might find that a simple thing like the PCV valve can cause problems that point to something else.

I was told when I got my '83 that the automatic transmission was shot. As I drove it the first time after I got it running, I noticed that it shifted really fast, and into third gear before it got up to 5 mph. I replaced a $14 part, the vacuum modulator, that controls the shift points with manifold vacuum, and all is well. Its not always the worst problems that wear you down, its the little ones that make things seem so much worse!!!

 

I've been told by a local shop, (one of which I actually trust), that on a lot of fords from the mid 70's to mid 80's had really ****ty valve guides and valve stem seals. The amount of oil that is ending up in my air cleaner is telling me that something just isn't right. It also sounds like it's got a horrible exhaust leak. Ticking like crazy. Either exhaust leak, or sticky lifter. The shop quoted me almost 300 to inspect, clean, and replace the valve guides. The new head is only 247. As soon as I get a little spare cash, I'm just gonna go ahead and order it. Can't hurt right? Those are the only problems with the truck though. Well, the back up lights kinda flicker when in reverse, but that is just a faulty switch i'm sure. If I put forward pressure on the shifter, the light stays on solid like it's supposed to.

 

Mine was running rich, but after a carb kit and some other adjustments, it doesn't have as much blowby into the crankcase. Blowing oil into the air cleaner means your pcv/egr system is clogged or wrong somehow. The crankcase has nowhere else to vent so it runs backwards, the easiest path, as it's just a hose and filter. Too much gas rinses the oil off the cylinders and mxes with the oil, thinning it, allowing more pressure to escape from the cylinders into the crankcase.

Check you oil and sniff the dipstick. Thin and gassy smelling means you need to look into the causes. Same problems as I had on my rig.

-Ed

 

I put a new egr on it last night and it didn't make a lick of difference. I did however find a couple vaccuum lines that weren't connected to anything. I need to figure out where they go so I can connect them again. I have a feeling I just need a new head. I'll order it in a couple weeks. I'm also thinking about taking the carb off and cleaning it out really good to see what happens.

 

I would rebuild the carb and change the oil and filter and give it a good tune up. Run a few tanks of gas thru it and get it good and warmed up. I bet the blowby that you have will go down. Are you in a hurry to spend alot of money on this old girl? Trust me. Spend money on getting it looking good, and run this motor until you save some money to do a total rebuild. But do the carburetor now!