Hello from Italy.
I own a 1982 GSL RX-7. I reckon it's the only one in the EU, as GSL was never imported across the Atlantic.
The car has 64k miles and runs perfectly (let's say 'smoothly' - read below). I drove it from Denmark to Italy when I first purchased it, and I still drive it happily - it starts cold, starts hot, all things work perfectly, except one: it's very slow.
I have always had the impression that it was underpowered from day one, then I finally put it on a rolling dyno bench, whose result matched my gut feeling: about 50 hp . Meh.

After a brief chat with the good guys at Mazdatrix, that I visit regularly when I go to LA once every year for business, I checked the leverage on the firewall side of the carb, to make sure that the 'T' linkage was not disconnected. It was OK.
However, that put me on the right track and after closer inspection, I soon realized also that the larger throttles (I think they are called the 'secondaries', right?) never open.

These throttles always stay closed
So I looked at these throttles and I found that their linkage to the diaphragm actuator is disconnected. Mistery solved - or so it seemed: the cotter pin is missing and therefore the throttle never open.
Unfortunately, the real issues seems to be that regardless of the pin, the large throttles are stuck. I tried to move them using their external linkage like the actuator would do, they are completely stuck.
The linkage itself is free to move inside the vacuum actuator's hole, like it should, but the throttle's shaft won't move at all when I apply some force on it.

So, before I remove the carb and try to understand what is causing the issue, I would like to know if there is anything else, that I am unaware of, preventing the secondary throttles from opening freely like they should.
Thanks!

 

Do you have the primary throttles open when you are trying to move the secondaries? There is a mechanical interlock that closes the secondaries when the primaries close. As such, they cannot open unless the primaries are open.

 

Peejay, I'll try that out. I've also found your other posts on this matter, very instructive.
I will let you know, thank you very much.

 

Not much luck for now. The secondaries appear to be locked solid. I have removed the vacuum actuator and the good news is that the membrane is working like it should.
I have generously sprayed WD40 on both external sides of the secondary shaft, but I haven't much hope - it feels seized.
I imagine a rebuild is necessary, therefore I need to buy a rebuild kit. I hope I can get the secondary shaft unstuck...
Which one would you recommend? Some YouTube videos suggest to get a Walker kit.

 

You may have to pull it off so you can deal with the secondaries in the throttle body. If a previous owner had disassembled the butterfly's and reassembled them incorrectly, they can get bound up and not move. When I did my Nikki mods this was something I had to carefully do when reassembling the secondaries after modifying the shaft and the screws for better flow. I had to leave them slightly loose and then slowly tighten while also moving the butterfly's through their full range. It took some patience and time to get it to move freely as intended.

 

Well, with some gentle tug of war, much WD40 and brake cleaner and overnight patience, the throttles came unstuck!
I had lost hope but in the end they started moving a little bit, more WD40, more cleaner, wash rinse repeat and they are now working properly.
I'm putting together everything now and can't wait to see how the car goes! I will let you know.

 

Oh - I had forgotten that I am waiting for a replacement master and repeater clutch pump, so not much driving around tonight
However, I've put everything together, and even in the garage, it sounds and takes RPM like it never did before. Can't wait to drive it next week
Many thanks for everyone's help.

 

I think you're going to be very happy, doubling your horsepower! Honestly it must have been pretty anemic with just the primaries.

 

I finally tried it last night, after replacing clutch master and repeater.
I guess the secondaries are opening like they should... judging by the fact that my son and I couldn't stop smiling
NOW those doritos are spinning!
It's like having a new car. Thank you all.

 

Glad you got it sorted out. Loved to see pics of your Lancia and Maserati. Italy has the coolest old cars.

 

Thank you.
I also happen to live between the flat and the hills, ideal driver's zone!