rear choke pull off needed?

[bruno]

i have a 17082224 carb on my 68 chevelle. i built this carb to cliffs specs with his kit. i had a bad choke coil, and am just now replacing it. looking in my manual for this carb, it appears it had a rear choke pull of as well as the front one. i currently only have the front one. do i need a rear one for this carb? it is an electric choke. not sure what other info you may need to help me. i haven’t driven the car yet, as it’s not ready. when i did fire it up, it seemed to run smooth, but couldn’t get it off high idle. i assume from the bad choke coil. just curious about the rear pull off now. thx.

[Cliff Ruggles]

Some of those later truck units used two choke pull-offs, most used one rear pull-off with two links on it.

I stock the pull-offs and electric choke coils.  My pull-offs are "timed" correctly.  I have to modify everything currently being sold because they don't have the correct release time.......Cliff

[bruno]

i believe i have another carb that has why looks like the correct rear pull off, i believe the number is 17082225 on that carb. i’ll check this evening and install that one for now, assuming it passes the test. i assume of course it is an original unit.
out of curiosity, what happens if i don’t have the rear pull off on? just the secondary air flaps opening too soon? or is there another function as well?

[bruno]

and because it’s been a while since i ordered anything from you, do you ship to canada? can’t remember if it was shipped to the border last time.

[Cliff Ruggles]

I ship to Canada and overseas daily.  It's actually pretty reasonable but may take a while since COVID gives everyone an excuse to be dysfunctional these days, especially USPS....

If the rear pull-off has two links it is the "primary" pull-off.  It's function is to unload the choke on a cold start and keep the secondary air flaps closed when the vacuum is high and keeps them from "whipping" open to fast when you go quickly to full throttle.

The front pull-off is optional and only a back-up for the rear one at this point. 

If the link to the secondaries comes from the front pull-off then it is the "primary" pull-off and does both functions mentioned above.  A rear pull-off, if used, becomes the secondary pull-off........

[bruno]

i think i understand,, but of course it’s not in front of me at the moment. if i get confused when i look at it tonight, i’ll post some pics of the two carbs. thx very much.

[bruno]

just looked at the 17082224 carb on the car, and it has the link for the air flaps coming from the front pull off. there are two screws where the rear pull off would mount, but i assume i do not need it at this point? or is there another function for it? trying to upload a pic from my phone but wrong format i guess. will keep trying.

[bruno]

hopefully this works

[77cruiser]

No you don't need it. I'm thinking the rear pulloff must be a emissions thing.