I've decided to replace my carburetor for a few reasons and I was hoping to get some advice.

The truck's a daily driver and i keep it stock. It has a single barrel carter yfa carb (#7468S). The original ford part number is long gone. The carb's given me an array of problems the most alarming of which is the gasoline in the oil. The dipstick gains even though there's an oil leak. I've replaced the fuel pump. I rebuilt the carb once and disassembled to clean it an additional two times. I've also done the plugs wires dizzy cap and timing. While i can't find a replacement screw-on-carb filter, I have added a glass inline filter due to concerns about a dirty gas tank. I get little flakes in there but not a lot. I spoke with a mechanic who told me that my gas tank would have to be a lot dirtier than it is to be causing such problems. He said the carb might just be shot and I should find a replacement. I seem to talk to a lot of mechanics who don't know what they're talking about but I'm out of solutions at this point. So anyway I've been changing the oil every week and driving this poor girl scout around for months now. I decided I'll clean the fuel tank with some gravel or something and buy a carb new.

So where should I start in finding a replacement? After doing some searching I can tell there were a lot of carter yfa models and I can't find a matching model. Would any of them match up? I keep my truck mostly stock and i do prefer the efficiency of the single barrel, but if someone would recommend an upgrade over going stock then maybe that's what I should do. I would prefer to just plug it up and go though I'd really prefer not to eliminate any of the emissions systems in there. I need to solve this problem before the cold weather comes. So what should I do?

 

same carb as you also

First few steps

clean your tank, if it is half as bad as mine, then you need to clean it out and probably patch a few pinholes

get a second inline fuel filter

get a fuel pressure gauge make sure everything is good

see if you can install a remote fuel cutoff solenoid. this way you can cut the fuel before you turn off your truck. this will help completely stop the gasoline dripping into the oil after shutdown

get a wideband oxygen sensor and see if you are running rich or lean (170 dollars from amazon is cheap compared to spending days and weeks changing oil.)

 

Talk to David/1986F150six. He's running a Carter YF 4901 from a 1970 F350 and getting excellent power and MPG from it.

Having said that, I've heard a lot about carbs being worn out, but I've never really found one. Yes, I've seen worn throttle shafts, but those can be bushed. However, I don't know what would cause you to have gas in the oil unless the accelerator pump diaphragm is split. And that's not a wear item in reality as it can easily be replaced.

However, if you are tired of the battle then see if you can find the YF as shown above. It sure works for David.

 

I have a similar problem, what happens on shutdown all of the gas drains from the carburetor and into the engine.

 

it's a lot cheaper to just inspect the spark plugs to see if you're running rich or lean.

 

I am very hesitant to say to check the plugs because, I am always afraid of the dust/rust/grime that likes to hang out around the spark plug wells will jump into the piston as soon as the spark plug is removed. Maybe because I haven't figured how to clean them out without using compressed air...

This is probably where a small can of compressed air might help? Do you know any perfect way to clean around spark plug before they are removed?

 

Exactly what you said. A little compressed air will clean out the junk around the plugs.
Of course the color/condition of the porcelain insulator on the plug's nose will tell you if the engine is running rich or lean or burning oil or misfiring.

NGK Spark Plugs USA

 

The Terrible Blob,

The carburetor I am using [previously described by Gary], was chosen due to a desire to simplify things during a conversion from the Feedback system original to my 1986 truck. 1970 was chosen to be prior to emissions [my EGR system is no longer operational].

Based on the fact that you stated that you would rather just have a replacement carburetor which you could mount and pretty much be ready to go, I found this for you @ Rock Auto.

More Information for AUTOLINE C6247

I looked at several pages, so I hope I copied the correct one. If not, go to Rock Auto's web site and find Ford, 1981, F150, 4.9L, fuel/air... two carburetors are listed; C6246 is for trucks w/o A/C; C6247 is for trucks with A/C. [you did not mention whether or not yours has A/C].

These carburetors are rebuilt by a company called Autoline, located in Canada. The one I received was well packaged, looked great and performed well out of the box. It only required a very tiny adjustment to the idle mixture and has continued to perform well for several years.

Hope this helps, if you decide to go the route of replacing your carburetor.

 

David - I would rep you if I could. SOMEONE, please rep David?

 

Done Gary.

 

Thanks, Ken. I'd rep you in exchange, but ......

 

I returned the favor, Gary.

Let's see, I think Ken scratched my back and now I am scratching his... but, you got left out!!!

 

It is the thought that counts. Thanks nonetheless.

 

Is that carb eletric choke compliant? Im going to be doing a swap in the first of the year. Id like a carb that would be pretty much a direct swap from my feedback.

 

Yes, the carburetor [link] has the electric choke. Keep in mind, the OP has a 1981 truck. Yours seems to be a 1986... different carburetor!

If you swap to an earlier [non-feedback] carburetor, you will affect the feedback system. Have you read about Duraspark conversions?