Throttle linkage adjustment question w/pics
#1
Racer
Thread Starter
Throttle linkage adjustment question w/pics
'72 350 with a Holly 4 bbl. I noticed the accelerator pedal dosen't have much range of motion til it hits the floor. I can't even get the other 2 bbls to kick in. Been trying to figure out how to adjust the linkage. Looked in the repair manual but I don't understand the verbage. Can anyone give me some pointers in laymans terms? Pis of my carb below.
#2
Drifting
Loosen this bolt, then slide the cable (and housing) back some. Then tighten.
Don't slide it back too far. It should still clamp mostly on the metal housing.
The other problem is the entire clamp and mount has probably pivoted forward at the carb bolt. You could try pivoting it back. I have this problem with my Holly as the stop tab is in a different place.
Don't slide it back too far. It should still clamp mostly on the metal housing.
The other problem is the entire clamp and mount has probably pivoted forward at the carb bolt. You could try pivoting it back. I have this problem with my Holly as the stop tab is in a different place.
#3
Heel & Toe
Member Since: Nov 2010
Location: Grand Rapids Michigan
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i had similar issue with mine. i ended up pulling the throttle cable and getting a crimp on cable stop from hardware store for 29 cents and put it about an inch in front of the stock location to allow for more peddle travel. its a bubba fix but it worked.
#5
Racer
Thread Starter
#6
Racer
Thread Starter
That idea crossed my mind. I think to gain access to the end of the cable I'd have to pull the dash. That thing is way up there and hard to see much less get a good hold on.
#7
Instructor
The Lokar cable is the best way to go. I just installed one on my 68 small block with a holly double pumper.
Remove the driver seat and get comfortable. There is one bolt holding the stock cable to the firewall, remove that and the acelerator pedal and arm. My pedal arm clamp that secures the pedal to the arm was worn and would alow the pedal rod to rotate before moving the flat stamped arm. Therefore a 1/4 to 3/8 loss of movement in the flat arm.
Replace the stamped arm.
Take out the old cable and cut off the firewall mounting tab, drill out to fit the Lokar cable housing attachment. Reinstall the new cable and secure with the bolt you removed. You will have to bend the flat throttle rod a bit to give you full throttle before the pedal hits the carpet.
On the carb end you need a better carb cable bracket that wont move when stomped on. Jegs has these as well as many others. Cut the cable housing as needed and the inner cable long, its easer to cut it again than throwing it in the garbage.
If interested I'll take a picture of it this weekend.
George
Remove the driver seat and get comfortable. There is one bolt holding the stock cable to the firewall, remove that and the acelerator pedal and arm. My pedal arm clamp that secures the pedal to the arm was worn and would alow the pedal rod to rotate before moving the flat stamped arm. Therefore a 1/4 to 3/8 loss of movement in the flat arm.
Replace the stamped arm.
Take out the old cable and cut off the firewall mounting tab, drill out to fit the Lokar cable housing attachment. Reinstall the new cable and secure with the bolt you removed. You will have to bend the flat throttle rod a bit to give you full throttle before the pedal hits the carpet.
On the carb end you need a better carb cable bracket that wont move when stomped on. Jegs has these as well as many others. Cut the cable housing as needed and the inner cable long, its easer to cut it again than throwing it in the garbage.
If interested I'll take a picture of it this weekend.
George
#9
Safety Car
I use these types of brackets for 100% adjustments.
You will get all of your pedal with them.
they are available from Summit or of ebay, name brand doesn't matter.
You will get all of your pedal with them.
they are available from Summit or of ebay, name brand doesn't matter.
#10
Racer
Thread Starter
I tried C6DuffMan's suggestion and adjusted the throttle cable in the clamp and repositioned the bracket back some. WOW! is all I can say. I've had this Vette for about 3 weeks now. It just seemed so sluggish and unresponsive. The last time I owned a C3 was about 25 years ago and I always remembered them having so much more power.
After I did the adjustment I took it out for a test drive. Got out on the highway and nailed it. Holy crap! Broke the tires loose shifting to second gear and pressed me into the seat back. That's what I'm talking about! Thanks for the suggestion.
Gonna look at a more premanent solution and will probably replace the throttle cable and bracket.
After I did the adjustment I took it out for a test drive. Got out on the highway and nailed it. Holy crap! Broke the tires loose shifting to second gear and pressed me into the seat back. That's what I'm talking about! Thanks for the suggestion.
Gonna look at a more premanent solution and will probably replace the throttle cable and bracket.
#11
Melting Slicks
Move the pivot on the carb to the upper hole. That will also give you some extra travel. The further from the butterflies, the more it moves them.
#12
I use this Bracket for my Demon Carb. I was somehow able to use the stock cable. Had to do a little low profile bubba to it.
#13
Intermediate
Hello
Had same prob on mine 72, linkage is probely for a Rochester carb.
Buy one for a Holley aka LT1 72 like this http://www.ecklerscorvette.com/corve...1969-1972.html
VonB
Had same prob on mine 72, linkage is probely for a Rochester carb.
Buy one for a Holley aka LT1 72 like this http://www.ecklerscorvette.com/corve...1969-1972.html
VonB
#15
Le Mans Master
You have the factory throttle cable setup on your carb. That exact same bracket has worked for me since 1969, thru countless carbs and manifolds, from the original tri-power all the way to the 2x4's to the current single Demon. I just can't see tossing cash at those really nice billet brackets when it can be used for performance you can feel/see.
It's all in the adjustment and position of the ball stud on the carb end throttle lever.
It's all in the adjustment and position of the ball stud on the carb end throttle lever.
#16
Racer
Thread Starter
Hello
Had same prob on mine 72, linkage is probely for a Rochester carb.
Buy one for a Holley aka LT1 72 like this http://www.ecklerscorvette.com/corve...1969-1972.html
VonB
Had same prob on mine 72, linkage is probely for a Rochester carb.
Buy one for a Holley aka LT1 72 like this http://www.ecklerscorvette.com/corve...1969-1972.html
VonB
#17
Le Mans Master
As normal, GM did some changing around on that bracket- early ones used the clamp, later years had a square that snapped into a bracket.
#18
#19
Racer
Thread Starter
I like the price of the one from Summit but I don't know if it can be modified to work with my cable. The one from Ecklers is a little pricey but will definately work. Here's one I found by doing a quick search on eBay. Looks like it may work with my cable. Just gotta check to see if I have a 4150 series carb.
http://cgi.ebay.com/ebaymotors/_W0QQ...KQ3aMEWAXQ3aIT
http://cgi.ebay.com/ebaymotors/_W0QQ...KQ3aMEWAXQ3aIT
#20
Melting Slicks
Member Since: Jul 2001
Location: Massapequa Park NY
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The cable should seat in the bracket against the shoulder/ridge on the cable. The pedal rod has a tendency to bend over time from repeated smashing to the floor The fix should be simply bending the rod up away from the floor to regain full travel and completely open the secondaries.
Jim
Jim