MFI throttle linkage question

[ThomasTe]

Are there different throttle pull rods fitted to the 1969-71 and 1972-73 MFI crossbars, or am I missing something else here?

I have just installed the correct 1972-73 MFI crossbar in my car. Some PO installed an incorrect 1969-71 crossbar. The difference is at the left-hand side, where the throttle pull rod connects.
The throttle pull rod fitted to the old 1969-71 crossbar is just not long enough to fit the 1972-73 version. The PET lists the same throttle pull rod (901.110.611.00) for both set-ups.

How can that be?

Is anybody able to measure the length of the correct 1972-73 pull rod with no ball sockets fitted?

Thanks in advance.

[RSTarga]

On my 73 about 29cm. 31.2 from end to end total including the socket housing.

[Flieger]

In my 1971 911S, I have a 2.7 RS spec built on a '74 7R case and using plastic intake runners. It has the "inverted V" shaped throttle linkage that you show for 1972->.

[ThomasTe]

Thanks, David.

The one I got is 24.5 cm without sockets.

If anyone has a correct 1973 pull rod (27.5 cm) for sale, I am in the market.

Flieger: Yes, the 911/83 engines (2.7RS 1972-74) has the V-shape, too

Thanks.

[gled49]

your 245mm rod is the early length. 275mm without the ends is the correct length for 72-73. Gordon

[BURN-BROS]

There are two length rods and 2 different bell cranks to go with the two different crossbars.

pic of the bellcranks ....early on the left.

[ThomasTe]

Thanks Aaron. The bellcrank I got is similar to the one to the right in your picture. I found this picture at Pelican of a ´72 bellcrank. It seems to confirm your info:

http://forums.pelicanparts.com/uploa...1195089264.jpg

Are you absolutely certain that the gold/cad bellcrank to the left in your picture is for 1969-71 MFI? The PET is not much help here. Only other bellcrank listed is for SPM 911E.

I have an old spare 2.2 throttle body, believed to be original. It is fitted with the bellcrank to the right in your picture.

Only difference between the two bellcranks in your picture seems to be the angle of the "V"-shape, which would make the actual distance it makes the pull rod move the same. I wonder what the idea behind this change in design is?

[BURN-BROS]

Are you absolutely certain that the gold/cad bellcrank to the left in your picture is for 1969-71 MFI? The PET is not much help here. Only other bellcrank listed is for SPM 911E.

LOL, I've come to the realization that nothing is for certain! I have bought mostly 69 injection systems. which has subtle differences. The gold cad part in the pic came from a 69 IIRC.....

Only difference between the two bellcranks in your picture seems to be the angle of the "V"-shape, which would make the actual distance it makes the pull rod move the same. I wonder what the idea behind this change in design is?

I think the change was to put the bellcrank in a better position at wide open throttle. Less stress on the plastic bushings.

Side note; There are 3 crossbars as far as I know. the 69 crossbar had no rib on the arms(like the one you posted). I am not sure when the ribs were introduced, but I would expect when they redesigned the throttles for 1970. There were a number of revisions for the throttle body castings throughout the 70-71 MY as well.


I try to use the narrow angle bellcranks when I can and make adjustments to the long rod to fit my needs. Here is a pic of a 70-71 setup I rebuilt and modded for big displacement street engines(3.2-3.5) or mid sized engines with big cams.

Pic of the "69" crossbar.