Carburetor linkage Questions for 67 Dart

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RatRod said:
Got some carb springs from auto zone and it looks like the carb linkage is hooked up right now based on the pictures you've all sent. Which were fabulous BTW.

How can I check the throttle linkage to see if it's hooked up right and not in need of replacement?
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Bad throttle cables are pretty obvious with the exterior coating cracked and the inner cable exposed. When that happens moisture can get in and start having the cable become very stiff and possibly jam. If the throttle cable looks good & allows the carb to return to idle as well as allowing the carb to go to wide open position when the gas pedal is stepped on to the floor... then I would not replace it. There is a long metal sleeve on the carb end of the cable that allows a little adjustment to ensure the cable both allows the carb to return to idle as well as permits WOT.
 
Have never installed a throttle cable so I have no experience with it.

How do you do a fine adjustment on the throttle cable using the metal sleeve that connects to the carb? Can you twist it right or left? Does it have to be disconnected first?

It looks like I have about 2" of cable showing and I assume that's the max amount it c/b adjusted?

Throttle linkage 67 Dart.jpg
 
RatRod said:
Have never installed a throttle cable so I have no experience with it.

How do you do a fine adjustment on the throttle cable using the metal sleeve that connects to the carb? Can you twist it right or left? Does it have to be disconnected first?

It looks like I have about 2" of cable showing and I assume that's the max amount it c/b adjusted?

View attachment 1716030918
Click to expand...
From the picture you sent, the metal sleeve is held in the bracket by the pinch bolt. To lengthen the cable you loosen the bolt and slide the metal sleeve toward the carb. Reverse to shorten it. When the choke is off, you want the slack taken out of the cable. Have a helper put the pedal all the way down and look to see if the carb is fully open. That will be the best you can do.
 
RatRod said:
Have never installed a throttle cable so I have no experience with it.

How do you do a fine adjustment on the throttle cable using the metal sleeve that connects to the carb? Can you twist it right or left? Does it have to be disconnected first?

It looks like I have about 2" of cable showing and I assume that's the max amount it c/b adjusted?

View attachment 1716030918
Click to expand...
Ricks70Duster340 said:
From the picture you sent, the metal sleeve is held in the bracket by the pinch bolt. To lengthen the cable you loosen the bolt and slide the metal sleeve toward the carb. Reverse to shorten it. When the choke is off, you want the slack taken out of the cable. Have a helper put the pedal all the way down and look to see if the carb is fully open. That will be the best you can do.
Click to expand...
And when you get the throttle cable adjusted, make sure you reattach the transmission linkage spring and adjust the linkage properly. Yours may be different than this one.

mopar kickdown linkage2.JPG
 
Please note that in many of the pics here there are double throttle return springs (one inside the other). Cheap insurance since the break in that little spring can keep the carb from closing and you're off to the races!!!

IMG_1002.JPG


IMG_1004.JPG
 
str12-340 said:
Please note that in many of the pics here there are double throttle return springs (one inside the other). Cheap insurance since the break in that little spring can keep the carb from closing and you're off to the races!!!
Click to expand...

Had a friend with a 65 Mustang. His throttle got caught in the wiring and held the throttle wide open. By the time he got it shut off the heads were trash.
 
str12-340 The pictures are great. After reviewing them and other pics that have been sent, I think my linkage setup is essentially correct. Traced it from the carb to the trans and visually it all seems to be there (auto 727). May need a minor throttle cable adjustment but not sure about that one yet.

What I did find was that at WOT my secondary jets aren't opening or even getting gas from what I can tell looking down into the carb (Eddy 1406 model and old) with the engine off and manually working the throttle at the carb.

I don't have the engine history on the car but it's been like this since I bought it and I'm just now getting around to it.

I was expecting to see the butterflies open at WOT but they don't move. The primaries move and I can see the gas.

Is the carb shot? What am I missing?

PXL_20230106_185100725.jpg
 
No you have to adjust the cable and auto kickdown to get idle and WOT. Looks like you need a 340 cable bracket.
 
@RatRod if you disconnect the throttle cable and the throttle pressure linkage from the carburetor, will the carb open all the way?

Try that first. If it dies, connect the throttle cable and try it again. If it still opens all the way, you'll know it's the throttle pressure linkage.
 
So this is gonna blow yer mind! This carb is based on the Carter AFB. To the right and left of the rear throttle plates is a counter weight that resists the back barrels from opening:
DSC04505.JPG

This is not a mechanical secondary carb. Rear barrels are opened on engine demand at higher RPMs
DSC04506.JPG

get your finger on the top of the counterweight and pull toward the front of the carb and you can open by hand
DSC04507.JPG

WOT is achieved by the front butterflies being straight up and down. This same situation is true of a vacuum secondary carb. There are also no accelerator pumps in the back barrels, like on a Holley double pumper so you can't expect to see a gas shot in the back barrels. This whole mechanism is why it is hard to "overcarburate" with these carbs - the back barrels only open based on engine demand and I don't think you can even rev the motor in Park or neutral enough to see them work because there is no load on the engine like when in gear.

As mentioned before the kick down system can keep you from adjusting this correctly.
Disconnect the kickdown arm at the throttle stud.
Adjust the cable (you need a partner in the car to floor the pedal) so that blades are straight up with the pedal floored.
The next step is alot easier if the car is up in the air like on 4 good jackstands.
Get your lovely assistant to lie under the car while you work the disconnected kick down from on top so that they can see how it works and then get them to work it back and forth for its whole range of motion.
The trick is to get the kickdown linkage to be all the way actuated with the throttle wide open. I don't understand how your system adjusts so figure that out, have your assistant hold the trans end of things all the way open and adjust the kickdown linkage so that at WOT the throttle stud, at the back of the slot against the spring, is holding the mechanism at the trans wide open.
THIS is the starting point.
Take the car out and make sure the trans kicks down when you floor it. Try it at multiple rolling speeds (10mph, 20, 30, 40).
Then launch it at 10 mph and see where the car shifts to the next gear on your tach. If it starts to rev too high let off!
If needed, back off the adjustment for the kick down so it shifts where you want it to. Remember this is what you are driving around on. If you go drag racing you can shift by hand and keep the car in the gear until the max RPM you are willing to risk. For example, if I had a street motor that I built for a 6000 rpm Max, I'd set the kick down to max out at 5500 or even 5000 for the street to protect my motor.

If some of this is unclear ask questions and we'll try to post more photos to explain.
 
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SRT- Thanks for explaining what's going on with the carb. Sounds like mine is okay so I'm going to move on.
 
STR, LOL that was a Freudian slip! Actually I thought you may have taken your moniker from the SRT Mopar badging but now I know better.

BTW I'm 67.
 
I just read back thru your note on the throttle linkage adjustment process and it's making sense to me. I need another person as I cant get my wife to go under the car! Are you available?
 
Sure... I could use a vacation in Desert Hot Springs during this Loooong, wet, cold, Western Washington Winter. That just outside Palm Springs, right? I seem to remember a hotel with a dozen swimming pools piped to various temperatures from the hot springs circa 1950s/60s... It even had poolside bar service - I felt like I was part of the Rat Pack.
 
That would be Miracle Hot springs and you can still get drinks by the pool. We usually go there once or twice a year.

SWA flies in daily to palm springs.
 
Been researching 727 Tran's on the forum and I read in one that there was a time when the 727 didnt have a "passing gear" option. I take the "passing gear" refers to the Kickdown feature on the trans. It goes on to mention a valve body difference in the tranny's.

Can anyone verify that?
 
RatRod said:
Been researching 727 Tran's on the forum and I read in one that there was a time when the 727 didnt have a "passing gear" option. I take the "passing gear" refers to the Kickdown feature on the trans. It goes on to mention a valve body difference in the tranny's.

Can anyone verify that?
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I can't think of a better source of information than Chrysler.
Off the top of my head the '67 transmission would not have the part-throttle kickdown. Regardless it has full a full throttle kickdown. The 'kickdown' is only one aspect of that linkage. The other more important one - is to increase hydraulic pressure going to various circuits in the transmission. It's interal to the design of the torqueflites or they will not shift right or hold the clutch packs firmly. (There's diagrams in color in the shop manual if you're curious)
Mattax said:
www.mymopar.com
You can download a '67 Service Manual and Master Tech Bulletins from here.

Also more explanation in the Master Tech Series. Available as pdf from the same website
1971 Transmission linkage adjustment supercedes the earlier ones. List of all the MTSC below
Master Technician Service Conference - Chrysler's Training for Mechanics
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Go with the 1971 Master Tech Conf updated adjustment advise.
Take a spring or whatever and have it hold the throttle lever on the transmission in the full forward position.
Yes it says use special tool XYZ, and while you don't have one, you can rig something to accomplish the mission.
Then go adjust the intermediate and throttle rods.
remove the spring contraption and install the throttle return springs.
See that the throttle movement begins to move the linkage immediately.
Check that the throttle can open fully and shut without hanging up.
Now its going to be right on, or fairly close.
 
so just to be clear, in 71 or 72 chrysler reworked their valve body in the trans (someone here knows the year, please chime in!). This is true for 727 and 904. Prior to that to get kick down (shift into "passing gear") required you to floor the accelerator. After that, there was a tuned kick down with a less than fully depressed pedal that was variable. You can install a later valve body into an earlier trans and it can be done in the car. Many manufacturers sell fully automatic valve bodies for a transmission that you want to update that also provide crisper shifts and less slippage (less wear and tear and better mileage). My favorite is the Cheatah Valve body available from A&A Transmission.
 
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