Throttle linkage CIS to Webers

[sgibson58]

I have recently rebuilt my '77 2.7s and changed from CIS to Webers. Now full movement of the accelerator pedal only gives me 50% throttle. Does anybody know of a fix?

[Eagledriver]

I don't know what the standard method is for this but you probably need to make sure you have the same bellcrank on the transmission pivot as the carbed (early) cars had. Other things to do are to adjust the pedal stop on the floor board and optimized the position of the other bell cranks to get the most movement you can from them.

-andy

[RichF]

I have the same problem and it is the bell crank, still havent found the right one, but almost got 100% when I adjusted the throttle linkage. The bell crank is a must. Anyone know which one it is?

[RWebb]

search on bell + crank for posts by me stating all I know re bell cranks

the arms differ in both length & in angle around the tube

[RichF]

RWebb I think I read those about a year ago and maybe it was you who cut and welded the old bell crank to make it fit right?? Thanks for the heads up.

[kucharskimb]

I had a problem with the bellcrank on the side of the transmission. The stock angle between centerlines was maybe 120 degrees or more. It needs to be closer to 45-50 degrees. The only way to successfully correct this was to cut one of the arms off very carefully by drilling/cutting out the old braze and then re-welding it to the correct angle.

This picture is probably closer to 70 deg. The correct centerline angle should be the same angle that the linkage changes direction, ie looking from the side it goes from 90 deg (level) to 45 deg (angled up) = 45deg. At the midpoint of the throw, the bellcrank arm should be perpendicular to its individual connecting rod/linkage.

(See below)

I also had to lengthen the diagonal rod. You can unscrew the ball end, then either find the correct size tubing and tap it or, in my case, bar stock. I drilled and tapped the bar stock to receive some threaded rod (both ends) and the ball end. I also had to make a custom length rod that connects the #3 bellcrank to the cross linkage.

Again, for all bellcranks, it is correctly aligned when the bellcrank arm and its linkage are at right angles halfway through the throw (between stop to WOT).

[kucharskimb]

[JP911]

It was necessary to shorten the throttle rod, which should get you close to 100%, but the bell crank pivot angles (mentioned) above are an issue as well.