I've got a '79 f150 with a 300 in it, Everything's great except for the carburetor The carb is having problems to say the least...
Numbers off the tag on the carb are: d9te-ma with a second line reading
a9e(?)7 the ? is either an I, L, or 1...
According to this page THE CARBURETOR SHOP / TRUCK CARBURETOR REPAIR KITS F Applications I have a carter YFA 7287 (took awhile to find due to semi-illegible tag)

Firstly, the choke is shot... Not worth fixing at this point as I've got an engine rebuild planned soon.


Secondly, after maybe 20 minutes to an hour of running, I start getting gas pouring out of it and running down the exhaust manifold.... needless to say this could cause some major issues.

I rebuilt the carb about six months ago, during the rebuild I (out of curiosity) dropped the float into a cup full of gasoline and was surprised to see that it sank to the bottom... Replacing the float fixed the problem for a month or 2, but now I'm getting the same thing again.

I also bought a rebuilt carb from a parts store, thinking maybe the problem was with mine... Nope, same problem with the new carb as well. (This was before I rebuilt the old one)

So what it looks like I'm going to have to do is get a brass float... Anyone know where I can find one?

Also, anyone know where I can get a vacuum diagram for my 300?

 

If the Carb Shop can't help, I don't know who can. What is the float made of? If plastic it can be welded.

Look in my albums for the vacuum diagram for my '81. If that doesn't help, I recall AutoZone used to have them on their website......lots of them! I think in the 'vehicle repair' link.

 

I think last time I got a float for mine, I just got it at my local autoparts store, like Napa or Autozone. They had an option of brass or nitrophyl.

Hrmm.... If you've bought a new carb, rebuilt a carb, replaced the float, etc. and this same fuel overflooding problem keeps occurring, that's bizarre, since I would think that problem would inherently be in the carb. Got a funky fuel pump that's putting out too much pressure?

Can you see where the fuel is leaking from?

 

Possibly, it is a mechanical pump.... Maybe floats set wrong?

 

Float settings wrong can really screw up a lot of stuff, and from what I've seen on the YFs, different years have different float settings.

 

On another note, what voltage should the electronic choke receive? Also if its not getting voltage should it be open or closed?

Also, is there an easy way to check the float setting, or do I have to take the carb apart?

 

The electronic choke on the YF should be getting about 7. More than that, and it'll burn up the coil in the choke housing.

The electricity warms the coil, which causes it to expand and open the choke plate. So, if it's not working, it'll remain closed (which will give terrible performance and gas mileage.)

 

Alright.... Mine sits wide open even with nothing connected.... think I'm gonna go rip the carb off, poke around...

 

If it sits wide open with nothing connected, I'm going to guess that the coil inside the choke housing has physically broken (happens). So, no coil is holding it closed when it's cool. A new housing isn't super expensive and would fix your choke.

Best of luck looking it over.

 

well.... what do ya know.... dumb*** that put the carb together forgot to make sure the coil engaged with the choke plate *facepalm*

Now I just gotta figure out why the plug's not getting enough juice, and possibly re-set the fast idle...

Any guesses on how much tension?

 

Wow, you think you'd notice that if you're putting a choke coil on, and then the choke flap is loose, you did something wrong! Nice find though, that should add a bit of drivability to the truck.

The wire on mine went directly from the choke element to a peg on the back of the alternator.

The fast idle was based on the choke moving linkage, so I imagine it'll have to be reset.

 

wow.... It starts up without 10 min of me sitting there! Now to see if it opens with the voltage its getting, and if so how long that takes...

 

Awesome! It's impressive what a working choke does. Should also eliminate a lot of running problems when its cold too.

 

now it flooded out, wont start, also there's gas fumes coming out the top of the carb... time to throw a rebuild kit at it, and found a brass float from knechts

 

Sounds like that's what it needs. I don't think anything can cause it to flood like that except the carb itself. Best of luck.