1982 Ford 300 Inline 6, Motorcraft Carb # 7640, 4WD, F250

Its been running great, but occasionally after I start it I have to get out and push the choke plate open once to get it off choke. I went to fix it and I found a few lines with screws in them and some unhooked lines. My Chilton doesn't give hardly any information on line routing for this setup.

1) Is there a place with more information about this specific setup and where the lines should run?

2) Where is this carburetor line with a screw in it supposed to go, and what does it do?



3) Where is this engine line with a screw in it supposed to go, and what does it do?



4) Where is this orange engine line supposed to go, and what does it do?



5) Where is this carburetor wire supposed to go, and what does it do? It didn't run to anything when I took it off the truck.



6) How do I set this choke? (the three screws that set the choke richness by turning it where loose when I took it off the truck)

7) Where does this threaded connection at the side of the choke assembly go to? Nothing was hooked up to it on my truck when I took it off (not my carb, but the same one off ebay)



8) Is there a routing diagram for the choke arm that is attached to the choke assembly by a bent wire? It appears that mine jambs and holds the choke from opening / closing.

Thanks guys, I appreciate the help.

 

It think I found a page that has some stuff on it. It appears someone basically unhooked the choke to the carb.

Carter Y, YF, YFA, YH, YS - The Carburetor Doctor

 

nice pictures, very clear, thanks I might need them soon.

 

The easiest place is the vacuum diagram on the emissions lable stuck to the top of the grill/radiator support bracket. If it's still there.

That is either for the EGR Valve and/or Vacuum advance, depending on calibration.

That is a manifold vacuum source. Not all of the ports are used on all models on the vacuum tree coming out of the intake. As example, If the truck had air conditioning, or never had air, one of the spots on this tree is for the climate controls in the cab, for trucks with air.

No way to know from the picture. I would need to see where this line plugs into.

That is a throttle control for the air conditioner system. When you turn the air conditioner on, there is increased load on the engine when the compressor engages. This device opens the throttle to keep the idle speed the same, energized with the air on, denergized with the air off. Some carbs were equipped with this solenoid, even when the truck did not come with air from the factory. The price for assymbly lines etc...

The three screws that hold the choke spring cap on, lossen them enough to turn the choke cap. You will see small marks on the carb, and one small mark on the choke spring cap. With the mark in the middle is normal. If the choke is adjustable, some are not, (it will say if it's adjustable on the emission sticker mentioned earlier), turn the cap one way for lean, the other for rich.

That is the heated choke stove connection. This is vital for proper choke operation. One line goes from the carb for fresh air. Pictured with the redish rubber hose, this hooks into a metal line that goes into the bottom of the exaust manifolds choke stove. The air is heated in the stove when the engine is warm, then goes out of the choke stove through a hole in the top of the exaust manifold directly above where the bottom hole is. Another metal tube is fitted and pressed into this hole. The other end of this tube goes to the threaded hole on the side of the carb next to the choke spring housing.

You can get this tube and fittings in the help section of most auto part stores. Universal Choke Stove Tube Repair kit.

Get yourself a carb rebuild kit. This kit has all the diagrams you need to rebuild the carb, and to adjust the choke properly.

 

Here is a diagram for the Carter YFA.

It's for a feedback carb, so parts on your carb will vary because you have a Carter YF.

But it will give you an Idea.

https://www.ford-trucks.com/user_gal...oid=97997&.jpg

The carb kit you buy will have a simular diagram for your application.

 

the choke pipe was broken off my carb.i put in a manual choke cable.not as nice as automatic choke but it works.takes some getting used to