Carb Options for 390

[FarmNut]

so I finally broke down and took my truck to a mechanic to get them to get it in "running" condition, then I could work from there. Because its really hard to run a farm without a truck. I needed it to pick up feed and hay this week.

Didn't help much, i just lost a bunch of money and time. Thats all.

So the one thing I am sure about now is the carb needs work and the fuel valve in the carb is in need of replacement.

My options are:
Rebuild the stock motocraft 2100
a) myself
b) have shop do it

I've had 50/50 say I can rebuild a carb and "hell no, its harder than you think! you'll screw it up!" What should I expect the price on that to be for a shop to rebuild? If i have a shop rebuild it for $300, then maybe I should spend another $50 and replace with new carb, which part of me just wants to do. Put something powerful on like an Edlebrock or Holly.

If I were to get a new carb how does a dummy like me determine if it will work with my 390 engine? All I knows is it needs be 4 cylinder and 600 or 650 cfm.

Yeah, I'm reading up but i really don't understand jack until i've got the parts in my hands and see how it works.

 

[Big Jim F150]

You mean a four barrel, instead of four cylinders. My thoughts would be towards a Holley 600 or 650 single pumper, for a double pumper would be too much carb for your engine which is a 390 . I have a Holley single pumper on my 78 F-150 Ranger Lariat with a 351M/400, but I am also running an Edelbrock intake manifold on mine, they were on it when I bought the truck and I have had good luck with that combo.

 

[Fellro]

The additional fuel itself isn't as much the issue as CFM's. 600-650 CFM is plenty for a stock 360-390.

Typical rebuild on a carb is essentially take the fuel bowls off, clean it all up, put new power valve in (newer style is updated and better) and put the gaskets in. Really isn't a lot of magic to carbs, main thing is that the internals are clean.

If you can't find a shop that has been around for a long time, it can be hard to find anyone that knows about carbs there. Fuel injection has been prominent long enough that there aren't as many shops that have any knowledge about what to do with them. It does tend to be a waste of time and money unless you find one of those shops.

Basic instructions on a rebuild, don't get hing up on all the different screw settings, many times you won't need to mess with them.
A bit more in depth:
http://hurtle.com/cars/mustang/fixes/carb/

Do a net search for "Motorcraft 2100 rebuild instructions" and you can find videos as well.
http://home.comcast.net/~liohn/MC2100/MC2100Rebuild.pdf

 

[FarmNut]

Finally did it and I noticed a few missing parts as i took it apart. Someone rebuilt before, but must have left a few things on the work bench....ord only know if ill get it put back together somewhat "right"

 

[Beach66Bum]

The rebuild kit should have the missing parts. Are you missing a linkage?

 

[Mil1ion]

Finally did it and I noticed a few missing parts as i took it apart. Someone rebuilt before, but must have left a few things on the work bench....ord only know if ill get it put back together somewhat "right"

One thing a lot of people who buy a rebuild kit (carb kit) don't realize that the important thing to recognize is the throttle rod bushings that wear amd leak causing engine running issues.
If a leak is discovered the only thing available to non machinists is to take your carb to parts house for them to either swap yours for another.
Or to have them send yours away to the carb rebuilding plant.

My point is...you may be flogging a dead carb.....hoping for utopia.

So.. What does your money go to ?

 

[Beach66Bum]

If visible signs of weeping at the throttle bushings is not visible, spraying carb cleaner around the base of the carb at that location... should not make a change in idle. If the idle changes, it is starting to leak at the bushing.

 

[FarmNut]

The part that I know of missing is the discharge check weight, which my kit does have. That would probably explain why the carb was getting flooded, right?

I totally agree with you, million. I was going to just chuck the carb and get a new one, but for $20 I opened up the carb, found out the probably. would never have figured it out without the parts list in the kit. The shop would have charged $800 to rebuild. for $20 I learned what the problem really was and learned about carbs and how they work! Hopefully at some point I will know enough that when i go to an auto shop they won't think of me as just a dumb woman they can swindle. one step closer to knowing my stuff.

if I actually get my carb to work then that just means i'm a magican

 

[Mil1ion]

If visible signs of weeping at the throttle bushings is not visible, spraying carb cleaner around the base of the carb at that location... should not make a change in idle. If the idle changes, it is starting to leak at the bushing.

I'm one of those that don't think people should spray anything flammable or messy at vacuum points.

I firmly believe people should use an unlit propane torch.

No mess and you can nestle the end right up close to vacuum leaking areas.

Makes much more sense.

 

[Mil1ion]

The part that I know of missing is the discharge check weight, which my kit does have. That would probably explain why the carb was getting flooded, right?

I totally agree with you, million. I was going to just chuck the carb and get a new one, but for $20 I opened up the carb, found out the probably. would never have figured it out without the parts list in the kit. The shop would have charged $800 to rebuild. for $20 I learned what the problem really was and learned about carbs and how they work! Hopefully at some point I will know enough that when i go to an auto shop they won't think of me as just a dumb woman they can swindle. one step closer to knowing my stuff.

if I actually get my carb to work then that just means i'm a magican

$800 ???..????

Who the hell do these people think they are ?

I get 4V Holleys carb kits installed for $40.

A replacement carb shouldn't be more than $150 after the core is submitted.


Good for you rebuilding it.
Float level is so important.
I lost a classic car in 1972 due to a bad carb rebuild. Burned to the ground.

 

[Fellro]

I will admit a propane torch is less messy, but just as dangerous as any other flammable substance, actually worse... WD 40 is messy, but not very flammable, and carb cleaner is minimally flammable, and evaporates.

I would venture to guess if they truly were going to charge that for a simple carb rebuild, they either didn't want the job due to not really knowing how, or were taking you for one hell of a ride. Had a shop take my sister on the 92, as they quoted one price to do the trans, then came out with a different one when done, claiming it was harder to change the trans due to it being a conversion.... It is no worse than stock!!!!! The install is just as clean as the factory did it! They nearly doubled their quote. I had the trans out in 1.5 hours, back in at 2 hours due to my own whoops forgetting to remove a bolt I had put in to hold the flywheel while tightening the bolts. They said they couldn't get the bell housing to clear the firewall. Well, they wouldn't get any more clearance had the 460 still been there!They apparently didn't know enough to let the motor tip down just a bit to get clearance... It was a medium/heavy duty shop, but damn!

Reman carbs around here are easily $200, and good luck on one that wasn't factory issue, I know of none that are available reman for performance type applications, only stock replacement.

 

[FarmNut]

so as it turns out my weight for the discharge check ball is missing and the part in the kit doesn't fit. I can't find a replacement part.

does this part really need to be there or even exist or did they just draw it on the rebuild diagram to confuse my little head?! this whole thing is related to the venturi cluster if what im saying doesn't make sense.