I guess I should start out by saying that I'm new here to the forums and I am currently going to school for auto mechanics

I'm planning on rebuilding the carb in my 1986 ford F 150 4.9 L with the single barrel carb. I was wondering what advice anyone has to help and any instructions would be helpful as the only thing I have is the exploited view that comes in the rebuild kit and have never done a carb rebuild before.

Thanks for any help in advance.

 

The only thing I can say about rebuilding carbs is relax. It is not as hard and complicating as people tend to think. Most of the problems I have fixed from people rebuilding their carbs is they worry too much and stress out, then make a simple mistake.
Make sure to clean everything, clean everything again. Then when you have the carb all cleaned up nice and all of the junk out of it, clean it again! If you can soak it in the dip cleaner.
Educate yourself on what makes the carb work. I also see a lot of people screw the idle mixture screws in and out trying to solve problems the screws have nothing to do with. Set them at low idle. Anything above low idle, the screws don't do anything.
Pay close attention to the float level when you set things. Make sure it is set level. Is this a motorcraft carb? If it is, the way I set the float is with the engine running. I set the float level on the bench. I throw away the little measuring stick that comes with some carb kits, and just set it level or just a hair below level. Then start the engine and remove the top of the carb, make sure the float is level when the engine is running. That is if it is a motorcraft carb.
When you take it apart, have a clean white cloth nearby to set your parts on as you pull them off the carb. There are some small check ***** and springs, make sure you don't lose any of those little *****.

 

Take pictures of the rods and levers before you take it apart. We just did the carb on my '81 300 and it took some time to figure out just how some of that was supposed to go.

 

First, welcome to FTE!!!

Good advice from both deputy and Mav. I'll add that a way to organize things helps, like even an old egg carton to put the parts in - just don't get cleaner on it.

Speaking of cleaner, don't leave the carb in the dipping cleaner very long as it will strip the coating. I prefer to use a spray carb or brake cleaner as it won't damage the metal and the little straw allows you to put concentrated spray in places to clean things. In fact, I use it to blow out all passages and holes - but watch out for blind holes as the stuff comes back at you. And, by the way, not all of those cleaners are created equal. I find that O'Reilly's house brand brake cleaner is as good as most carb cleaners and far better than some other brake cleaners.

But, I disagree about setting float levels. While I don't use the flimsy little rules they send in the kits, preferring a drill bit instead, I religiously set the level to the specs provided. Also, google rebuilding that carb and you will find several how-to videos that are quite helpful.

 

Get a cookie sheet or something similar to put underneath the carb when taking it apart. That will prevent losing any little check ***** or clips that you may drop. It will also prevent left over gasoline from spilling on the floor.

DO NOT take everything apart. If you read the instructions in the kit, one of the first things they tell you is to only take it apart enough to clean it. You do not have to take every little lever and piece off the carb and do not take the throttle blade off the shaft in the bottom of the carb. Take the main pieces loose so you can get to the passageways, and that's it. Make sure not to spray the plastic pieces and the electronic pieces on the carb, these are parts that you need to take off or move out of the way so cleaner does not melt them.

I see you are new, and am wondering do you know your truck originally had a computer? And your carb is a electronic version? Are all the wires and hoses hooked up on this engine? A lot of people disconnect that stuff, and then the computer doesn't work right and the old 300 doesn't run as good as it could and your mpg will be down.

 

thank you for all your help I will defiantly use the tips to keep it organized and keep from losing parts.

Franklin2 im not to sure how to tell, as there are electrical connectors in the area but im not sure what all is in it because its a relativity new truck to me only had it for year. what am I looking for see if it is electrical or not ??

 

Look for a vacuum advance unit with a vacuum line mounted to the distributor. If you do not have one, then your truck has the computer control on it. If it's all original, and everything is still hooked up and working fine, then good. If a bunch of stuff is disconnected and plugged off, then you may have a problem. It would be the same as disconnecting a bunch of stuff on a fuel injected engine. It will go into limp home mode and keep the engine running, but your power and fuel mileage will suffer. It also controlled the fuel mixture with a solenoid that screws into the carb.

 

If the carburetor has a solenoid on the driver's side with wires [2?] going to it as well as a single wire connected to the choke housing and a throttle position sensor [connected to the throttle shaft], then it is known as a "feedback" carburetor and is part of the original ignition system found on most 1984-1986 [49 state] 4.9L engines.

Also, look at the base of the distributor [driver's side of engine]. Does it have several small wires [not the plug wires] or does it have a vacuum hose? This will tell us if the system has been converted to Duraspark [older type ignition; pre computer].

Welcome to the forum!

Here is a link to a photo of the "feedback" carburetor.
http://www.ebay.com/itm/ROS-CARTER-YFA-CARBURETOR-7599S-1984-FORD-TRUCKS-300-CI-6-CYLINDER-ENGINE-AOT-/271293946871?pt=Motors_Car_Truck_Parts_Accessories&hash=item3f2a611bf7&vxp=mtr#ht_538wt_1133

 

as i recall it is the feedabck model i know there is a wired thing on the side don't rember what its called but I was told not to break it because its expesive and yes it dose have wires on coming from the distrubator.

 

Which means your distributor probably looks like this:



(Except yours will have more connections on the distributor cap, and there'll be a big electrical connector going to the module mounted on the distributor)

 

You're lucky in that you have the Carter carburetor, because it is very easy to rebuild. I was a total n00b when it came to carburetors a couple of years ago when I redid mine, and I can tell you that if you relax, take photos as you go, and follow the directions exactly you won't have any problems.

I'll also second what Gary said - those specs are provided for a reason, use them.

 

i found a video of how to rebuild a carb but it is the non feedback version is there any big differences in rebuilding a non feedback as there is to a feedback carb ??? because the video seems like its right just want to make sure

 

and yes cubutis that is what mine looks like

 

I don't think there is a major difference between the non-feedback and feedback carbs. But, that's my expectation and is not based on having them in front of me at the same time. So, I think the video will apply pretty closely. However, I've seen many videos on that carb so don't quite looking for them after the first one as there probably is at least one on the feedback version.

 

can anyone explain to me how the choke works? its an electric choke but mine is always open even when its below freezing out... and I don't understand why. if you have a digram that explains that would be great