Quadrajet Problem Solving > Diagnose a Quadrajet carburetor problem

Choke Pulloff - Marine Carb just rebuilt

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429bbf:
greg .it was posted earlier you need cfm demand to get them to open .sitting in the drive way snapping the throttle isnt enough demand the only way they will open is if you remove the pulloff link and set the spring tension very light .that was the great design of the quad it only gives the engine the fuel and air it needs. dean

5stareventsdj:
Thanks again. I was out working on it again. I started cold. Although the choke is opening fullly, it's taking a long time to do it (10 minutes). It's a divorced choke and the linkage is nearly straight. I may look for a new bitmattalic spring. In the meantime, I am going to adjust the spring in the housing.

I shut the engine off after it was warmed up and was playing with the fast idle cam, trying to figure out how it works. While moving the throttle back and forth, I noticed drops of gas coming from the throttle shaft, near the fast idle adjustment. Does this mean I need to do the throttle bushings? When I had the carb off to rebuild it I didn't feel any play. Is there a gasket that may need to be replaced? My instincts tell me that if gas can come out there that air can get it. This was not happening while the engine was running just when it was off.

Lastly, I was able to confirm that the secondary throttle is working properly. If I push down the air flaps, I can see them opening when I move the throttle.

Would a leak in the throttle shaft be enough to cause the engine to run lean at WOT and cause me not reach WOT RPMs?

Sorry for so many questions. It's my first carb and I don't want to give up on it.

Greg

Shark Racer:

--- Quote from: 5stareventsdj on October 08, 2012, 12:18:32 PM ---
1. Does this mean I need to do the throttle bushings? When I had the carb off to rebuild it I didn't feel any play. Is there a gasket that may need to be replaced? My instincts tell me that if gas can come out there that air can get it. This was not happening while the engine was running just when it was off.

2. Would a leak in the throttle shaft be enough to cause the engine to run lean at WOT and cause me not reach WOT RPMs?

--- End quote ---

1. The only gasket to worry about there is the throttle body-main body gasket. Did it seal well? Is there any chance your main body was missing the alignment dowels to the throttle body? (there should be two). If they are missing, Cliff has a procedure in his book that describes how to align the throttle body with the main body.

2. Not likely. The secondaries are massive and the amount of air that could get through the shaft area is minimal.

5stareventsdj:

--- Quote from: Shark Racer on October 08, 2012, 01:13:07 PM ---1. The only gasket to worry about there is the throttle body-main body gasket. Did it seal well? Is there any chance your main body was missing the alignment dowels to the throttle body? (there should be two). If they are missing, Cliff has a procedure in his book that describes how to align the throttle body with the main body.
--- End quote ---
Yes that gasket sealed well. The only time gas comes out is when I pump the throttle while the engine is not running. The dowels were there. Alignment went nice.

--- Quote from: Shark Racer on October 08, 2012, 01:13:07 PM ---2. Not likely. The secondaries are massive and the amount of air that could get through the shaft area is minimal.

--- End quote ---
Good to know. Should I be concerned that gas is coming out of the throttle shaft? It only happens when I pump the throttle and the engine isn't running.

Going back out now to mess with the choke. Hopefully it's cold enough.
Greg

Shark Racer:
I would be concerned about the fuel coming out. Especially on the primary side.

I was responding to the vac leak @ WOT. Something that minor shouldn't have a huge, if any, impact on WOT. It could have a massive effect on idle, though.

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