accelleration lag

[4eyedblonde]

Will a lean or rich A/F setting cause the engine to lag or stumble a little when you punch the throttle? Or is it timing related? I'm set at 18 deg now, no idea what total is though. 750 Holley DP on the engine (440)

 

[Meep-Meep]

Slightly lean or rich may not be noticed when stomping on it. That has more to do with accelerator pump that covers the gap between idle and when the engine generates enough velocity to get the main discharge working. You may just have a simple case of too much carb, too much cam, not enough compression or timing curve off. But 18 deg BTDC should be adequate so may not be timing. Factory carb settings for that 750 DP should work fairly well so you may have other issues. Start by getting rid of the DP and use a smaller vac secondary.

 

[67 coronet]

make sure your accelerator pumps are working ok by moving the throttle by hand while looking down into the carb.all squirters should have a steady flow and start right when you begin to move the throttle.a torn accelerator pump will cause the prob you described.is this a new issue or has it been there since assembled?