Holley stumble trouble

SSG_Karg said

30cc pumps front/rear. 28 squirter front 31 rear.
I don’t think it has anything to do with the acc pump. If I mat the throttle it takes off, no hesitation or stumble at all. Only hiccup is during very light throttle cruise when starting to give it a hair more throttle. Just a half second hiccup then smoothes back out. If I get into the throttle quickly it doesn’t stumble. Seems like the transition is not lasting long enough until the mains can take over.

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On my Holley set ups i always ran 50 cc shot pump with a very fast linkage cam.
I dont know what your running for initial timing but ya might try backing off the timing a bit like if your at 18* back it down to 16* this will bring down the idle rpm then you can add idle rpm with the idle screw on the linkage. That will open up the transfer slot allowing for better transition. I had to do that on my BBM stroker or it would stumble bad on the transition.
side note: I recently found out that may old trusty Mac timing light was off 3*