Quadrajet & 75k5

[TCLARK]

I have a 75K5 with a 40 over, flat top pistons, 202 heads, roller tip rockers, aluminum intake, headers w/balance pipes 350 & 350TH. It runs good, idles good & starts good after the first start off the primaries. I can't seem to get the secondaries to kick in, I think the linkage is out of whack. Now when you give it gas under load ( pulling a 24' pontoon ) it starts missing, let off of it and it runs good. Is this the carb or coil bad?

[70inline6]

In my experience, coils either work or they don't, independent of throttle position. From what you're describing, missing under load, I'd say the carb is leaning out. You need to find out why the secondary plate isn't opening (which will allow more fuel to flow in).

[TCLARK]

Originally Posted by 70inline6

In my experience, coils either work or they don't, independent of throttle position. From what you're describing, missing under load, I'd say the carb is leaning out. You need to find out why the secondary plate isn't opening (which will allow more fuel to flow in).

Could it be the linkage not adjusted right? The secondaries seem to open in Park in the driveway. I have had coils that work fine in the driveway & miss out on the road.

[bilfman]

I have had the same issue with qjets in the past and with my experience getting them working properly after they start acting up is a bear. I went out and got a 4bbl Edelbrock this last time and I could not be happier with the carb. Starts like a fuel injected engine, has great throttle response and excellent power. After owning the edelbrock unit I will never go back to a qjet, and I have had qjets for 20+ years.

Install is simple, kit is complete and setup can be done by a 4 year old. The carb I got came with an install dvd, even someone who has NEVER turned a wrench could follow it.

3 thumbs up for it over the q jet.

Don't get me wrong a properly running and tuned qjet is an amazing carb. But the simplicity and ease of the edelbrock makes it a clear winer in my books.

[TCLARK]

Originally Posted by bilfman

I have had the same issue with qjets in the past and with my experience getting them working properly after they start acting up is a bear. I went out and got a 4bbl Edelbrock this last time and I could not be happier with the carb. Starts like a fuel injected engine, has great throttle response and excellent power. After owning the edelbrock unit I will never go back to a qjet, and I have had qjets for 20+ years.

Install is simple, kit is complete and setup can be done by a 4 year old. The carb I got came with an install dvd, even someone who has NEVER turned a wrench could follow it.

3 thumbs up for it over the q jet.

Don't get me wrong a properly running and tuned qjet is an amazing carb. But the simplicity and ease of the edelbrock makes it a clear winer in my books.

I have an Edelbrock on my Stingray, it is a pretty good carb ( does flood once in a while ). This Quadrajet is in good shape, I rebuilt it a few years ago and new bushing installed, I think the secondaries just need adjusted.

[Corts60]

There is a secondary lock out mechanism that is on the pass. side and is one of the levers that goes to your choke assembly and/or vacuum pot, depending on what q-jet you have. If you look at the secondary throttle shaft on that side, you will see that little tab that locks it out. Make sure that that lock out tab is adjusted properly or your secondary butterflies will not open. You may have to fiddle with or remove the choke pot to get at it. It's been awhile since I've adjusted one of those so I can't remember exactly how to do it.

[TCLARK]

Originally Posted by Corts60

There is a secondary lock out mechanism that is on the pass. side and is one of the levers that goes to your choke assembly and/or vacuum pot, depending on what q-jet you have. If you look at the secondary throttle shaft on that side, you will see that little tab that locks it out. Make sure that that lock out tab is adjusted properly or your secondary butterflies will not open. You may have to fiddle with or remove the choke pot to get at it. It's been awhile since I've adjusted one of those so I can't remember exactly how to do it.

I think the linkage has been bent so many times is the problem, the secondaries have never worked right since I've owned it. I can't find anything on adjusting this linkage. I have an old Quadrajet I may have to take the linkage from and replace it????