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Quadrajet

antijam

CCCUK Member
I'm looking to overhaul the Quadrajet (Rochester Part No. 7041213) on my '71 350. Rebuild kits are readily available but despite scouring the internet I can't find a supplier for the secondary vacuum break - arrowed in the piccie below.... (mine is defunct, I need a new one)

break.jpg

Does anyone know of a source for this part? Any help would be much appreciated.
 

antijam

CCCUK Member
Thanks for the link Nick - unfortunately it's not the same as mine which has a double slotted actuator (see piccie below)

P1320123.JPG

The upper angled slot is linked to the secondary chokes, the lower one via a bellcrank to the divorced choke spring. I've found several vacuum break pull offs with this type of actuator (this one for example) but none listed as suitable for my carb. I guess they're all basically on/off devices so perhaps If I find one with the right actuator it can be used to replace my original?
 
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Jimbo64

CCCUK Member
Thanks for the link Nick - unfortunately it's not the same as mine which has a double slotted actuator (see piccie below)

View attachment 2980

The upper angled slot is linked to the secondary chokes, the lower one via a bellcrank to the divorced choke spring. I've found several vacuum break pull offs with this type of actuator (this one for example) but none listed as suitable for my carb. I guess they're all basically on/off devices so perhaps If I find one with the right actuator it can be used to replace my original?
If that's what it's supposed to look like, then no wonder my one wasn't working on my carb and I do feel even more vindicated by swapping out my clearly defunct Rochester for an Edelbrock 600, which to date, is running very nicely. I did initially buy a refurb kit, but as you stated, didn't come with any parts for the above, so wasn't of much use to me, once I saw the state of my secondary chokes. Sadly, can't offer up any help with where to get any of the above, just commenting on how different a set up is on yours to mine, so apologies for just rambling!!
 

antijam

CCCUK Member
If that's what it's supposed to look like, then no wonder my one wasn't working on my carb and I do feel even more vindicated by swapping out my clearly defunct Rochester for an Edelbrock 600, which to date, is running very nicely. I did initially buy a refurb kit, but as you stated, didn't come with any parts for the above, so wasn't of much use to me, once I saw the state of my secondary chokes. Sadly, can't offer up any help with where to get any of the above, just commenting on how different a set up is on yours to mine, so apologies for just rambling!!
Interesting that you should say that Jimbo - I'd assumed that my carb set-up was original, but this is my first Vette and with a car nearly 50 years old you can never be quite sure what might have happened to it during its long life. Certainly the carb is the correct one for the motor and year and the pull off looks as if it's never been off, but apparently the correct pull off for this carb looks like this....

Capture.JPG

...which is nothing like mine. I'm wondering if your original looked the same? (assuming we have the same motor - 350 base/270 HP?)

Any way the plot has thickened somewhat since the reason I originally suspected a possible dodgy pull off was a severe tendency for the engine to 'bog' when quick acceleration was demanded. This I attributed to possibly the acceleration pump or the pull off not working and checking the pull off with a vacuum pump produced no movement. Aha, I think, that's the problem! However when I reconnected the vacuum line yesterday and started the engine to check the acceleration pump, lo and behold - the pull off now works!

So, for the moment I've ditched the search for a new pull off; I've ordered a rebuild kit for carb and when it arrives I'll strip it down, clean it up, replace the acceleration pump and see if the overhaul improves matters. Hopefully I won't have to follow your example and invest in an Edelbrock, but it's good to know that works for you.
 

Jimbo64

CCCUK Member
Interesting that you should say that Jimbo - I'd assumed that my carb set-up was original, but this is my first Vette and with a car nearly 50 years old you can never be quite sure what might have happened to it during its long life. Certainly the carb is the correct one for the motor and year and the pull off looks as if it's never been off, but apparently the correct pull off for this carb looks like this....

View attachment 3005

...which is nothing like mine. I'm wondering if your original looked the same? (assuming we have the same motor - 350 base/270 HP?)

Any way the plot has thickened somewhat since the reason I originally suspected a possible dodgy pull off was a severe tendency for the engine to 'bog' when quick acceleration was demanded. This I attributed to possibly the acceleration pump or the pull off not working and checking the pull off with a vacuum pump produced no movement. Aha, I think, that's the problem! However when I reconnected the vacuum line yesterday and started the engine to check the acceleration pump, lo and behold - the pull off now works!

So, for the moment I've ditched the search for a new pull off; I've ordered a rebuild kit for carb and when it arrives I'll strip it down, clean it up, replace the acceleration pump and see if the overhaul improves matters. Hopefully I won't have to follow your example and invest in an Edelbrock, but it's good to know that works for you.
Looks like I've deleted the pictures I took of the set up I had, but from memory, it didn't look like what you have in picture. Mine clearly had been replaced, as it looked far newer than rest of carb. Together with the fact that there was soldered on bits in mine, where in videos, Haynes manual pictures that I compared, this was a screwed in piece to allow unit to be fixed in place, made me realise mine had been "amended" for engine to idle/run, but under acceleration had worked for a bit, then failed and allowed carb to flood.
 
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