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When I put the gas pedal to the floor the car bogs down and I loose power. The set up I am running is a 302 with a cam, headers, hi-rise shelby intake and a holley 650cfm double pumper that was new as of last year. I have the carb set right when the book told me (about 1.25 turns out from all the way it)and have tried richen the gas/air mix a little to 1.5 turns but this shows little improvement. Do I need to richen more? Jet up? Get a samller carb? Vaccum readings are good and the timing is advanced a little. I also run about a 100 octane gas. the motor is good. Any help would be great.
 

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The double pumper is a whole lot of carb for a small block..I would think when those mechanical secondaries open it is causing your motor to bog..not sure how to fix it other then get a carb with vacuum secondaries.You didn't mention if you were running a manual or an auto tranny..auto's dont respond well with mech secondaries..you also didn't mention what rear gearing you are running..
 

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Your accellerator pump may need adjustment or may not be working at all.

Take the air cleaner off, look down the primary (front) venturis and open the throttle. You should see two streams of gasoline spray, one for each venturi.
 

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I vote for too much carburetor. The secondaries are opening and your airflow velocity is going to zero. Not much you can do to solve this problem with a DP carb. Adjust the secondaries to open later (if you can).
 

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Make sure you also check your vac advance on the distributor. I just had the same problem with a 390. The diaphram was bad on the advance, and did not advance the timing thru higher RPM's. Good luck, Jack.
 
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