info on throttle linkage

[sparkie573]

So I was messing with putting on a new filter on the car today. and just wanted to check this since one of my buddies had the same problem on his car. I had my girlfriend push the throttle down to the floor normal without mashing it in while I looked down the carb. And low and behold it only barely opens the secondaries. But if she pushes the pedal to the floor and then mashes it in hard it does open them a bit further, still not all the way though.. I thought maybe I could loosen the clamp and pull the cable back a bit but as soon as you do it bumps the primarys open so that isn't going to work I don't think. There doesn't seem to be any slack at all in the cable, It just doesnt have enough travel to open the carb all the way. So I am wondering what I am needing to fix this. A shorter cable, A different bracket of some sort, or what else??? any help, info, opinion? Thanks.

It is a 71 scamp. stock throttle cable and pedal.
408 stroker with eddlebrock air gap intake.
aed carb.
some sort of jeggs brand throttle & return spring bracket.

 

[sparkie573]

So this is how little the secondaries open.

 

[Bad Sport]

Typically the secondaries aren't going to open until the engine is under load, driven at WOT.

 

[PA Dodger]

While I can't tell you what part exactly will fix your problem, what you need is more of a lever effect. It's a Holley carb so you need the Holley bracket made for mopars that raises the throttle cable and gives it more range.

 

[Snake]

that is not a vacuum secondary carb right,I think your problim is the rod that opens your secondary is bent wrong there is an adjustment that sometimes to be done its got to much of a bend it needs to straight i can see in your pic the rod does not even sit against that leaver.

 

[Big Block Hippie]

You need the linkage up higher to get the full pull needed

 

[jbc426]

Agreed, your throttle cable attaches to the wrong place on the carb. It's too close to the centerline of the throttle shaft on the carb. You need to make or buy an extension so the cable attaches farther away from the throttle shaft centerline.

 

[OldmanRick]

You need the linkage up higher to get the full pull needed

Agreed, your throttle cable attaches to the wrong place on the carb. It's too close to the centerline of the throttle shaft on the carb. You need to make or buy an extension so the cable attaches farther away from the throttle shaft centerline.

Not to be a poo poo head, but if the cable travel is limited....moving it further away from the fulcrum will lessen the amount of throttle travel.

that is not a vacuum secondary carb right,I think your problim is the rod that opens your secondary is bent wrong there is an adjustment that sometimes to be done its got to much of a bend it needs to straight i can see in your pic the rod does not even sit against that leaver.

Snake, that's a good observation on the link and it can be tweaked, but it's where it is because these carbs are set to start the secondary opening at 30*to 50* of primary opening. They are not set to be 1 to 1.

This is a little hard to diagnose over the net. I think your existing cable should have more travel then it's showing. I would disconnect from the carb and see how much travel it actually has. There may be a issue at the pedal side?

I say this assuming with the cable unhooked the carb works properly. If not, there could be throttle plate to gasket interference.

 

[67Dart273]

I agree with RIck. It's been a LOOONNNGG time since I've had a Mopar/ Holley, but seems to me I used to put a bolt in the hole UNDER the very large hole to get enough "throw."

First order of business is to see if the carb works OK on it's own.

I don't know anything about those brackets, but my cable bracket were always lower vertically than this one.

 

[sparkie573]

Hey thanks. No, its not a vaccum secondarie. I thought also that maybe it was getting some interferance but nope. While she had her foot to the floor I pulled the throttle back the rest of the way and it opened fine. Also if she, mashed her foot into to the floor it would open slightly more but still nowhere all the way. So the problem is caused by either cable or bracket. Does anyone know a part number for a lever extension or bracket I may need? I will check on the cable at the pedal end. Thanks great help I appreciate it.

 

[TrailBeast]

The cable won't change anything itself.
Either the connection of the cable to the carb need to be moved more towards the butterfly shaft, or there needs to be more travel of the cable at the pedal.
I think you may find that this is the interference right here.
I don't think the cable is being allowed to travel all the way back, and if I am right about this then a different bracket will be needed.

 

[bad440]

if that was a 2 barrel originaly that cable leaves a little to be desired . spectre makes a decent 20 dollar cable kit.and you can make it any length you need it.or a lokar is a good setup also....

 

[sparkie573]

That is what I was thinking is that there needs to be more travel at the cable because it seems the pedal hits the floor before the carb is open all the way. And at the carb end it seems there could be enough cable pull, but its just that the pedal is at the floor already... What would be the difference in the 4 barrel throttle cables and 2 barrels?

 

[Oldmanmopar]

You need to add this bracket to the carb. It changes the fulcrum point. Then move your cable to the ouside of the cable bracket. These are available from holley , Mopar linkage adapter.

 

[Snake]

Thanksssssssssss oldmanrick for setting me straight.Great help here guys.

 

[sparkie573]

I was hoping it was that I just needed a some sort of bracket extension. I'm ordering the holley 20-7 bracket extension. Hope that gets it... THANKS ALL.

 

[sparkie573]

Well Awesome. got the 20-7 holley throttle bracket in finally and went to install it and found that it won't clear the throttle cable bracket and return spring setup that is currently on it. even better I'm pretty sure I had a throttle bracket that would have worked but traded it with some other parts for a heater box and controls set up... back to the drawring board. I may just try and fab something.

 

[4spdragtop]

So its hitting the black bracket that is below the linkage?? And hitting the 2 throttle return springs?? Post pics if you can...also one of the 20-7 linkage

 

[sparkie573]

yeaap. the 20-7 bracket as installed, but it looks like it would just move the linkage out away from the carb, but not up away from butterfly centerline for more leverage or travel? and yes it hits both the black throttle linkage bracket and also silver return spring bracket. Anyone any suggestions? I was hoping that I had a stock style linkage bracket that bolts to the manifold but no luck as I had stated I believe I traded it off, I may have to go on a hunt for one. GRRRR.

 

[4spdragtop]

I may have a throttle linkage...send me a pm and i will get back to you in the am