Quadrajet Nghtmare

WYOROGER

Cadet
Joined
Aug 29, 2010
Messages
7
I have a 1989 OMC Cobra 5.7L with Rochester Quadrajet carburetor. Runs fine on the primaries, but once you call upon the secondaries, she will all but die. I pulled the spark arrestor and had a buddy drive while I looked into the throat of the carburetor. When you get on the throttle, the secondary plates open, but the secondary on right "dribbles" gas while on the left you can see no fuel flow. Just had the carburetor rebuilt, but from reading the various threads this may mean little or nothing, because I'm still witnessing the same thing. Secondaries open, fuel dribbles from right and no fuel flow visible on left secondary.

Any help/hints are greatly aprpeciated.
 

WILSONS88

Petty Officer 3rd Class
Joined
Jun 29, 2011
Messages
75
Re: Quadrajet Nghtmare

Could be the float is set to low and its not getting the fuel it needs. What was it doing before the rebuild?
 

WYOROGER

Cadet
Joined
Aug 29, 2010
Messages
7
Re: Quadrajet Nghtmare

The symptoms, over the past couple of years, have been progressively less power , longer to plane out, missing at high rpms and the fuel dribbling out of the port side secondary and no apparent fuel out of starboard side. This was both prior to and since rebuild. I didn't do the rebuild, had it done at a recommended local shop ("not many folks know carburation anymore) and I don't know the rebuild kit number. A slowly sinking float makes sense. Would a float have come with a rebuild kit? After paying $275 for the rebuild, I see on the internet there are a number of "professional" rebuilders out in cyberspace. Anybody have any recommendations ... I'm too novice to dive into the world of springs, floats and check balls to try and set my own.

Thanks.
 

John_S

Rear Admiral
Joined
Jun 21, 2004
Messages
4,269
Re: Quadrajet Nghtmare

The symptoms, over the past couple of years, have been progressively less power , longer to plane out, missing at high rpms and the fuel dribbling out of the port side secondary and no apparent fuel out of starboard side. This was both prior to and since rebuild. I didn't do the rebuild, had it done at a recommended local shop ("not many folks know carburation anymore) and I don't know the rebuild kit number. A slowly sinking float makes sense. Would a float have come with a rebuild kit? After paying $275 for the rebuild, I see on the internet there are a number of "professional" rebuilders out in cyberspace. Anybody have any recommendations ... I'm too novice to dive into the world of springs, floats and check balls to try and set my own.
Thanks.

A new float would not come with rebuild kit. But, a rebuilder should check all parts, and not just throw a kit at anyway. There is only one bowl and one float in Q-jet. I don't understand why the diff between side of secondary, outside of what was mentioned, bad rebuild. What has the rebuilder have to say about your issue?
 

stackz

Master Chief Petty Officer
Joined
May 29, 2008
Messages
830
Re: Quadrajet Nghtmare

sounds like all they did was tear the carb open and toss a new gasket set in there without pulling all the jets/orifices and cleaning the internal passageways of debris/blockage.

does the carb body look any newer/cleaner than before to say it was dipped in carb cleaner over night at least? I've seen shops clean a carb by spraying the outside of the body with brake parts cleaner and calling it a day :/
 
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