Flat spot with a Carter YF?

[Econoline]

It's probably a bit rich off idle. Like said, maybe the mixture screw is to far out with the idle screw to far in, getting into the transition, or maybe it's jetted slightly to high. If you can get the intial timing up a bit and back off the idle mixture may help or fix it all together. Otherwise I would look to swapping the jet and/or rod with the next size down.

http://www.carburetor-blog.com/carter-y ... arburetor/

 

[Asa]

Having messed with this enough, interesting setup.

If you back off the accel adjustment the engine doesn't run at all. Set it to factory specs and you get the flatspot. I think I have it tuned out but it needed messing with a couple other settings related to idle, unfortunately the trade off is that the idle is a little higher than I'd really like. I've got a tach incoming, but I'm currently researching how to read the RPM with my multimeter.

If I have to mess with it anymore, I might try to find another top half of the carb, build it properly, then drill a hole just over the adjustment screw. At that point I'll play with it till it's right then swap halves.
What a pain adjusting this thing is.

 

[wsa111]

Give us some specs on the engine, cam, compression.
What are the distributor specs. Total centrifugal advance starting @? & total @ ?. Vacuum advance total??
Do you use ported vacuum source or manifold vacuum?? Bill

 

[Asa]

Stock engine from a '65 If I remember right, DSII ignition, one of Mike's dual exhaust kits, otherwise stock. Compression was bumped a little bit when I replaced the head, but not anything outrageous.
I'll have to figure the advance out, I want to say that the starting advance is 12 degrees, haven't messed with the dizzy at all so total advance would be whatever is in it from stock.

I'm using the same port as shown in this picture
http://i.imgur.com/vCagHMD.jpg

 

[Asa]

So, now that I have got Susie moved over to the new house (not a 100% uneventful trip http://i.imgur.com/dIjNQ6a.png) figuring out how to fix this carburetor is not necessarily a priority.

I'm pondering if I should get the appropriate carburetor for the head/ignition combo I have in place. I'm not finding many sources that can supply a Carter YFA and guarantee it comes from the right engine.

 

[xctasy]

So, now that I have got Susie moved over to the new house (not a 100% uneventful trip http://i.imgur.com/dIjNQ6a.png) figuring out how to fix this carburetor is not necessarily a priority.

I'm pondering if I should get the appropriate carburetor for the head/ignition combo I have in place. I'm not finding many sources that can supply a Carter YFA and guarantee it comes from the right engine.

Frankenstangs 173 dollar Evil Bay YFA....or any other kind that supports your US industry. You'll always get a 1.6875" throttle with 1.3" venturi


A YFA that size supplies fuel for a 72 hp net 2 liter Ranger, or a 120 hp net 4.9 liter F150.

You don't need no freekin "guarantee it comes from the right engine".

Early YF on a 4bbl 350 Chebby V8 18.1:1 air fuel
https://www.youtube.com/watch?v=tLiLtidMN5s



4.9 Liter YFA on a 4bbl 350 Chebby V8 18.1:1 air fuel
https://www.youtube.com/watch?v=4-uqOJyp504

Any YFA will be effectively an Autolite 1101 or big venturi Holley 1940/1945/1946

All of them were the same size. Its only the early pre 1972 YFA's that had the quirky cfm variations as described in the Falcon Six Pefrormance book. Buying off line, any BIG sIX YFA will do.

 

[Asa]

Trying to decode this for now. If I can't I'll look at buying a new carb.
Metering Rod part number looks like 75-2079? It's a bit rounded off on the edge

Tip diameter is .045", but I'm not sure where to measure the other measurement I keep seeing referenced online. Just above the taper? If so it looks like it's somewhere between .079 and .080"

Any of those numbers make any sense?

 

[xctasy]

see below

 

[xctasy]

Yup. 10 up from the bottom, page 241. 75-2079. Exactly it.

http://www.troberg-larsen.priv.no/mopar ... g_rods.jpg.

Main jet should be 98. 120-398 Carter code.

600 series Edelbrock 4-bbl main jets

Main jets:
Size: Carter: Edelbrock: Jet call name, Ford call name
.098 120-398 1427; fits #75-2079, (Blue line underneath). Its possibly similar to 1969 240 F100 carb tag # C8UF-M
.101 120-401 1429; *
.104 120-404 1430; *
.107 120-407 1431; #75-2175 or 75-2176 (Red lines underneath)
.110 120-410 1432; #75-2346 *

*= D2 prefix are all for 1972 engines;
the only D2 carb showing for a 72 300 has a main jet of .110",
all the rest (four) are for 240's,
three of which call for a .104" jet
and the fourth one is .101".

From "Converting to a Carter YF and Throttle Cable" Post #39 by xctasy » Sat Apr 25, 2015

Metering Rods to be added to this post as info comes to hand

From 56mulberry

viewtopic.php?f=2&t=51599

75-2189 is leanest F100 1977 300 Metering Rod, whic will be with the .107 jet.

75-1862 is a common 3 step Jeep 258 needle Overall Length: 2.58" "Power Tip" Diameter: .045" Cruise Rod Diameter: .075"

Care of John Strenk at JeepForum.Com

post #7 of 14 Old 12-26-2009, 07:25 AM
http://www.jeepforum.com/forum/f8/carte ... ch-932262/

This is THE gif for the YF Carter, all types.

And this is the adjustment

About the only thing that will bite is the inclusion in some Ford YFA's of a Metering Rod Arm Plate, with a hole ID: .185" and overall length of 1.050"

Starting 1973, SOME Ford YFA's got a TSB for adding washers to the metering rod arm to make it work better on hills.

Its also 1977 on wards to approx 1980 Ford TSB Part, called a "step-up limiter shim", found on some off road Fords, that is sold by QuadraJet parts under PN # 2584G https://quadrajetparts.com/metering-rod ... -1166.html.

Don't use it if some one has put it in.

Some rebuilders put platic metering rod arm protectors , a so called "anti-rock" plate from a 1980 and later Carter YFA's. They don't help an early carb.

 

[Asa]

Two day shipping.
https://smile.amazon.com/Edelbrock-1427 ... 00068OQG0/

Other than a rebuild kit, anything else that might be useful? Any other jets that need to be changed?

 

[xctasy]

Read above. Post 29 has some upgrades.


Its the other check weights, and other parts that may/might have been added in a rebuild that cause the problems with a YF.

Like looking in a black room for a black cat that insn't there, or trying to find the missing high wind sign.

Unless you know what to look for, where, you won't know what is missing.

Great to see some iresistable energy apllied to Susie!

I love your work, and thanks for keeping the world Civil dude.

 

[Asa]

Well, Florida doesn't have too many hills. I'll keep an eye out for that washer in my junkyard crawls.

Went looking for other stuff available through the Carb Parts website and my choke's coils and such are missing so I ordered a electric choke conversion, a rebuild kit, and a couple other odds and ends.

Did I post the video from that second pic?

https://www.youtube.com/watch?v=ihhj4ZW6JJ8

 

[xctasy]

nope...but me like....

 

[bubba22349]

Well, Florida doesn't have too many hills. I'll keep an eye out for that washer in my junkyard crawls.

Went looking for other stuff available through the Carb Parts website and my choke's coils and such are missing so I ordered a electric choke conversion, a rebuild kit, and a couple other odds and ends.

Did I post the video from that second pic?

https://www.youtube.com/watch?v=ihhj4ZW6JJ8

Well ether that engine is still a bit cold from the lack of a working choke or maybe your accelerator pump shot could use some adjusting. Engine sounds great though good luck.

 

[Asa]

X, have the carb parts and have the carb soaking in some Berryman's. Before I threw it in I pulled the jet and it looks like the numbers on it are 120-407. Considering the rod I have, does that make sense for how bad the flatspot is there?

What was that jet even for? I didn't find it on Mikes' Carb Parts.

 

[xctasy]

X, have the carb parts and have the carb soaking in some Berryman's. Before I threw it in I pulled the jet and it looks like the numbers on it are 120-407. Considering the rod I have, does that make sense for how bad the flatspot is there?

What was that jet even for? I didn't find it on Mikes' Carb Parts.

A color tune or narrow band air fuel meter gives yo a dial in. So do most service stations.

:wow:

Yes, 98 "thou". ".098"

LazyJW

Early 240's,three of which call for a .104" jet and the fourth one is .101".,

170s, 200's had to be less for sure. You wouldn't jet a metering rod .107, thats rich. It'd just bog. It DOES just bog.

240's and 250's made only 100 hp net despite there 145 and 155 gross ratings, so why would 170/200 YF's have .107

Everything else is later 1972 on is 240/300, and bigger.

Its very important to understand that despite what you might see in old Ak Miller literature, the call numbers for the after Autolite sell off in 1970, the Ford store/counter bought carbs denote Carter YF numbers D0 TF 9510 G, instead of the earlier Autolite D0 ZZ 9510 M.


Mikes carbs don't carry everything.

Mike's supe smart, and only supplys whats needed.

Most (not all) of the current aftermarket repair kits contain a fuel valve designed for the Ford engine which has an orifice of .101 inches. The fuel valve as used in ALL of the YF carbs for Chevrolet L6's 194/230/250/292 had an orifice size of just .081 inches.

Early 170/200's simply don't rate at .107's unless you can find a jet that is thicker.


Any of the short coded items have 9510 after the first four letters, with G Automatic Choke, F manual choke and, IIRC, for E exhaust heated line included.

The http://www.carbkitsource.com/manuals/ca ... CM059.html

lists
C8AF-BF
C8AF-V
C8UF-G
C8UF-M
C9TF-E
C9TF-M
D0AF-A
D0AF-B
D0BF-A
D0DF-A
D0DF-B
D0DF-C
D0DF-D
D0DF-E
D0DF-F
D0DF-G
D0DF-H
D0DF-L
D0DF-M
D0DF-R
D0DF-S
D0DF-T
D0DF-U
D0PF-AA
D0PF-AC
D0PF-AD
D0TF-E
D0TF-F
D0TF-G
D0TF-J
D0TF-K
D0TF-L

 

[Asa]

If that's a .098, then isn't that what I just bought? Will there be a change with this?

 

[xctasy]

Nope, no jet change. Its a lean jet, right on the bottom of the Carter Rich to Lean Range.


I'm pickin that someone has messed around with an aftermarket kit, and that's what was mixed and matched. I guess you don't have a carb tag on that thing, do ya?



Your 107 jet is WAY too rich for the metering rod, the 98 should lean it back and stop the bog. Unmoddifed, a 200 Ford with a YF and nice igntion wouldn't be much more tha a 65 rwhp engine, 77 with headers. Net at the flywheel, 97 hp. Same as the 240. The AMC 199 / 232 / 258 like .101 jets. One 1973 Rambler manual and for a 232, automatic calls for .098 jet.

Even hard core peformance cars like turbo charged Chevy Corvairs used the similar YH carb, and only used 81 jets stock, and the Black Hawk Engineering reprofile service is only for sub 94 thou jets. 4 Cylinder Army Jeeps ran less than 93.5 thou.

Anything else bigger than 94 you can get, but Big Six stuff is Bigger Stuff than Small Six stuff.

You know, a little like the awfull 1978 to 1983 era where you couldn't find Jack Sh8@+ about Motorcraft carbs and Throttle Body Injection.

You can't find a 67 to 72 YFA needle size on the early stuff,

Ford wasn't supporting Carter in the late 60's and 1970, not untill Autolite was forced to go bust because of the Governments Anti Trust laws.

Ford really wanted to do there own stuff, and sell it off like happened eventually with Motorcraft, they didn't want to buy Carter carbs.


Chevy replaced all there Carter YF carbs in 1968 with its own Rochester brand carbs, the Fed's didn't force them to sell off Rochester Reproductions.

Holley was its performance go to producer.

Ford just picked up all the Chevy lost Carter production, and fattened up the main jets and ran its own profile rods, just like AMC.

By the time Autolite were no longer doing exclusive Ford business, the D0-TF-9510-G carb, by Carter, was rated at 233 cfm, while the 144 Holley replacment cubic carb was listed as 150 cfm. Both carbs were supplied by Autolite, from another carb maker. See The Complete Ford Book, Page 42, post #1 on https://www.jalopyjournal.com/forum/thr ... 452/page-2


Oh yeah while I'm at have you checked your balls yet?

 

[Asa]

The accelerator pump on the old carb was absolutely shot. Need to start using ethanol free gas or something to protect the rubber.

Just checked the ball and it looks like it's a 9/64.

Also, frustratingly, I believe I clicked on the wrong rebuild kit from Mike's. Need a K4073, got a K4317, so I'll need to start a return. Wondering what the difference is now

 

[xctasy]

http://www.carburetor-parts.com/YF-Jet- ... p_729.html


Best list yet.


Officially, I've found the Chev played with .1023 jets (I'm calling them hereon, 102.3 thou)
Ford started with 98's, then went up in Emissions era carbs to the 101, 104, 107, 110's.

They even got down to 92 jet sizes in some manual 170 and 200 engines in the Maverics and such like.

So you can call em whatever you like.

For a 67, use a 98, and the lean metering rod you have already.

I can't find a breakout of OEM metering rods.