Have most folks *deleted* the fuel screen on their Motorcraft 2100 Carbs? For those still running this carb (2 barrel).

For whatever reason, the one in my carb is a bit squirrely from a thread perspective. I've tested several of the supposedly correct filter assemblies and they do not go in as they should (definitely want to strip the carb's inlet threading). I sent a pic to the folks at Mike's Carbs, and ordered their best guess on what should work (there are only two options supposedly). But they did say the screen did indeed look 'different' to them from what they are used to. I include a schematic below to reference the part. It looks like any other to me, with the flat inlet portion rather than concave.

Anyhow, I'm tempted to hit my old one with a bunch of carb cleaner and reinstall it. But what would make more sense to me is to simply get rid of it and add an inline filter. I would probably do that before the fuel pump and then fit a short length of pipe to the carb, then switching to a rubber line from the fuel pump.

If people have done that...is the fitting for the carb just a regular fuel line fitting? I'd guess it is 5/16 or so but don't really know.

As a final aside, it does not look like someone rethreaded the carb inlet. The thing looks like it's been left alone for eons.

Thanks, John

 

The one on mine loves to leak if it’s not beared down on super tight. Much tighter than I want to tighten it into the carb body.

 

Over the years I’ve seen a few deleted and a hose barb/nipple put in its place. But far away most that I’ve seen still have a filter screwed into the inlet.

i’ve never personally had a problem with any of the ones I’ve had, so never a reason to delete it. But I don’t think it’s a major problem either way.
I simply like having a filter after the pump just as the factory designed it. In case the pump starts deteriorating and putting some debris into the system. So an in-line version like you were talking about, but after the pump instead of before it, would I think the best. And more easily accessible for service as well.

Otherwise the fuel system can be designed as you see fit. And yes while I think most are 5/16, some are 3/8 so just base it on the outlet size of the pump. I believe my pump inlet was 3/8 along with the rest of the fuel system back to the tanks.
But I can’t remember exactly what size is at the carb on my ‘79.
I just want to say 5/16.

 

You call it a "screen". Motorcraft has an 8 micron filter (FG14 C) which looks like it "might" be correct for your application.


FG14C

I agree that it would be best to have one just before the carburetor, though many pumps have their own filter.

 

Thanks gents. I hadn't thought about the fuel pump crapping out and pumping junk into the carb. Great point. I had planned on an inline filter before the pump because I've heard of people damaging their pumps with grit in their fuel (though the screen on the sender should prevent that I'd think).

I'm going to give that last one a shot (thanks for the image). If that doesn't work...I'll put the old one in per your suggestions and add an inline filter before the pump.

As far as calling it a screen....I call it a filter too, but the guys at Mikes Carb corrected me and said it's actual a screen. Sure enough, when I looked into one of them I could see it was indeed a screen. Who knew. John

 

You could always get one of these. The carb filters do need to be tight after years of over tightening. I use a box end wrench on them. Your picture is kind of oriented kind of wonky but the 9F525 is also a screen under the needle seat and not often replaced.

 

You can call it either way. There are different types of filters, but they're still a filter whether it's a pleated paper or synthetic element, or a metal or synthetic mesh screen. The intent is still to "filter" out impurities.

If you ever get the chance, you might just check the "sock filter" (no idea how they make them or what they make them out of) on your sender to make sure it's still there. Many of them are practically pristine, but many are either deteriorated, or completely missing. Have found some on the bottom of the tanks after slipping off the tube, while others have been found in small chunks laying around the tank.
Does not hurt to find out, then renew it if needed.

Paul

 

Yes. I've pulled both my tanks in prep for resealing them. The socks are still there but should be replaced, they've got a weird flaky powder all over them which I assume is some sort of fuel residue. I will probably try to reuse the senders since I hear the new ones are kind of junky.

5158A. thanks for the pic. I have the newer style which I don't think has a filter in it. But I really don't know for sure. I'm replacing that too given they are pretty inexpensive on Rockauto.

My latest mistake has been removal of the hood today. I've got stuck hood hinge bolts on both sides now...given the age and design of the captured nut. Had to cut off two of them...and two more to go. Can not for the life of me understand the design of this, but I'm guessing there is a good reason. Will be interesting when I can really get a clear look at the inner fenders and what is going on. Thanks for the advice on the filter. John

 

Just reviving a dead thread of my own making...

I just found the original screen (filter) for the carb which had gone missing a long while. This is a big deal because every replacement I bought doesn't want to screw in more than half way. Pic below for reference.

My question is how many of you (if any) have copper washers (crush washers) on that inlet?

The replacement I got had one. And the instructions for the rebuild referenced one. But my original didn't have any. I suspect damaged threads from someone in the distant past (note condition of threading on that filter) make this a possibly important step. Just want to minimize how many times I crank down on this filter given how hard it was to get it out. If no one uses them, I will skip. I was strongly advised against any use of teflon tape because of risk of it coming off in bowl etc.

 

It's a pipe thread, right?

You should use some of that heavier yellow "safe for gas" tape or something else gas proof to seal the threads. Trying to tighten pipe threads (if that's what it is) into aluminum tight enough to hold gasoline is impossible.

If you are careful you won't have any getting in the bowl.

 

that makes sense to me but the folks at Mike's Carbs said anything like that is a no-no (perhaps they're assuming people will go nuts with the tape...for gas and black pipe I usually use actual gas compliant pipe dope rather than tape...wonder if that might work). Have you used it on yours? Or a crush washer? Problem with the truck is it is new to me and bought as a non-runner so I don't know if the missing tape/washer was an issue. I suspect not given how tight it was on and no evidence of ever being removed.

how did they make it work from the factory with these motorcraft 2100's? Just allowing alum. threading to deform as filter went in?

Oh so many questions!!!! I'm making this too complicated I'm sure.

 

Probably it is best to have the filter without any gasoline leaking. If you need to add something to the threads to make a seal, use something that the gasoline will not dissolve. If you use a tape don't put it too far forward on the male part. Leave the first thread without tape. In some situations I have used sewing thread carefully placed in the threads just to "take up" a bit of looseness in a loose connection.

 

I’ve never seen any type of washer in that position. But I could see if the thread allowed the filter to bottom out on the carb before fully tight, trying a washer would be on the list.

in the old days I never used Teflon tape on a carb filter. No problems.
Now I use it fairly often. Also no problems.

But I also use great care because of the dire warnings that everyone has put out ever since I can remember.
I think we were warned off of Teflon tape back in the 70s for use with fuel lines for just the reasons you have been quoted.
But also like you thought, I think the warnings you said were geared towards those who would use it indiscriminately or without care.

but hey, if there’s a better product I’m all for it.

 

Thanks all....appreciate the answers. John