Car Lacks some power before secondaries?

[Kcity78Fiat]

I have a 1978 124 sport spider which I am slowly resurrecting. I purchased a brand new carb from SoCalMark, car idles beautifully after I adjusted the idle mixture screw to a nice smooth idle, good vacuum on a gauge is showing. The dilema I am coming across is that just before I get into the secondary, say driving up an incline, the car starts to hesitate. Almost like it is running lean? Once the secondary opens up, she runs like a top, and accelerates very nicely. Anyone have a similar problem? Please let me know.

Thanks,
Kyle

[So Cal Mark]

The carb may be jetted on the lean side. You'll need to check the fuel mixture to be sure