i have a 74 f100 with a 240 i6 that has just been rebuilt and need some advice on the carb. i have a rebuild kit for a yf type 1bbl but have never done any carb word before. i'm going to try to rebuild it because to order one is ten times the cost of the kit. any suggestions or helpfull hints would be great. without a lot of mechanical background or experience, am i getting in over my head? thanks for any help.

 

Thats one of the simplest to go thru. the kit should have a pretty good pic and directions. Blow it out good and check the throttle shaft bushings. these can be redone, and if bad will cause poor idle.

 

I have rebuilt several carbs of all types. One thing I know for sure is they like to be clean. I use a 1 gallon can of carb cleaner I bought at the local parts store. It comes with a basket for small parts and does a good job eating old crud. I will advise though wear some gloves, it ate up my hands good last time I used it for an extended period. One other thing, follow the directions that come with the kit, you'll be ok.

 

Recently posted simular topic on a first time rebuilt. With advice from other FTE members really pleased with results. Was going to suggest search under topic but appears already got some good advice. Would let set overnight in can of carb cleaner. Not sure if applys w/ the model carb you will be working on, but i did not soak anything that i felt would be damaged by the chemical solution, plastic, rubber, etc. Also suggestion getting can or two of the aerosol carb cleaner for cleaning air passages. Clean area a must. If you do not have a compressor may want to get can of the compressed air used for cleaning electronic or computer equipment. Have not tried it myself but a thought.

dave

 

thanks to all for the tips. as it turns out the throtle body has a bit of play in it. looks like i'm trying to decide between taking it to a local guy that says he can garuntee it to pass emissions testing and will do all adjustments for the first year, or order a rebuit one from napa. i like the idea of supporting a local mechanic, and have heard that even a rebuild from a parts store may have throtle body leakage. prices are close, because shipping is outrageous. so it looks like my first rebuild will have to wait for another project. would i be better off getting a weber or other brand? i'm not comfortable with doing bushing and i'm getting anxious to get her running again. any help or suggestions are appreciated. thanks again
jason

 

What kind of emissions are you worried about in a 74? Nobody really got hard core until 1975, except good ol' cali... Sorry for my ignorance but us here in Ohio don't do emissions tests, except maybe Cleveland. BTW I had access to a 5 gas analyzer a while back so I was tweaking my carb ('69 351W, 2V, stock) to set to 69 spec of 14:1 air/fuel ratio, and later to find even without cats it ran clean enough at idle to pass 1985 emission standards.
As for which carb to use, use whatever it was originally equipped with. One other thing be sure you exhaust is in good shape with no leaks, before your test.

 

I would like to warn you about the problems that come along with remanufactured carbs from auto parts stores. When you buy it, you have no idea about the quality of labor or parts used, and the seals often are dried up from too much shelf time.

Anyway, if you do decide to rebuild your carb, try to work with the gallon can stuff outside with plenty of air. Even if you just open it and have it inside for just a little bit of time, the whole place can end up smelling like a hospital. But it really helps getting the job done. I use it in conjunction with a can or two of the spray.

As for the emmissions testing, I think simply rebuilding the carb will play a big part in passing the tests...just make sure you get everything very clean. You mentioned in your first test that your engine is rebuilt, another plus. If you have any smog equipment on your motor then check it out. I'm not sure if EGR was put on the 240's in '74 but it was around at the time.

Can you find another throttle body for your rebuild? I wouldn't trust a reman. carb to have a tight throttle shaft. I read a story on another thread of a guy buying a reman. carb and the bushings actually fell out.

Just my 2 cents...