If you have low compression /nearly stock motor the carb could be too big. My first motor I ever built was a .030 over 400 with stock pistons, 2.02 double hump heads and a ERSON HI-FLO 1 hydraulic cam ( .472 lift DUR @ 50 WAS ABOUT 230) I put a brand new 700 DP on it...every time I floored it it fell flat on it's face...ease into it it was fine. That carb had a 50cc pump on the rear.I tried bigger squirters and all that with no luck. I got a 650 DP that was box stock and nearly new...it had the small 30cc pump front and rear...That thing came to life in a big way! Instant throttle response. Car felt 3 times faster too.
edit: I should have read the whole thread beforte reply...didn't know it was a vacume secondary carb.
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