I just got done putting a Holley HP main body on my 650 dp 2-corner idle carb. After the install, it idled great and started right up. WOT is fantastic and feels leaps and bounds better than just the plain jane 650 dp.

Part throttle (below say 40%) is what's the bugger. I can cruise all day long, but as soon as I give it a touch more gas to get a few more mph, it stumbles and chokes itself. If I go beyond 40% throttle, it really starts to pick up great and feels fine again all the way to redline.

What can I check? Float levels? I think the primary float may still be a touch low, but will that cause this much of a problem?

Anything else I can try?

 

Get the float levels right first. Until you do that, nothing else will be productive.

If it still does it after the float levels are correct, make sure your accelerator pump is operating properly. If that's okay and it still does it, try a higher number power valve.

 

thats a classic sign of a weak pumpshot...play with the different color accelerator pump cams installed in the top or bottom holes of each. After finding the pump cam that improves the condition the best, go up one size at a time on the primary squirter if you still have a slight tip in bog. What size power valve do you have in it now? how much vacuum is the motor pulling in idle and in gear?