Stumped and Frustrated with a Holley 670 Hesitation

Whats dragging? Bendix? slow starter?


I dont know if this helps.but my 4150 has a whistle at idle and it has never ran as good as this. I could be way wrong but I was hoping that was a good sign?


Change plugs and make another pass?

Try the pink pump cam (longer squirt beter transition) and or next size down on acell discharge nozzle? (may help stumble on WOT same affect as the pink cam)
Are your cams in #1?
any slop in acell pump screw to pump diaphragm arm? (remove any to .015 at WOT) Hold throttle wide open and check with fealer gauge.


If you truly do need more fule and have zero vaccum leaks than look to a 50cc acell pump diaphragm, hollow discharge screws and 40+ acell discharge nozzels...

Are you running a drop base aircleaner? If so it may need some hammer love to clear the throttle an kickdown linkage... mine hung up bad an now I test that the pedal snaps back before any fire hits the engine..