Originally Posted by kleen56
I'm running a 4777 650 cfm Holley. The carb runs well, linkage adjusted correctly, jetting is fine. When I crack the throttle, I get a studder but then it clears. I was told to replace the discharge nozzles to correct this problem. I know I have 25 nozzles in the primary and 32 in the secondary. Any suggestions on which way to go as far as sizing? I've already dont the accelerator cam routine. Carb is running great except for the stumble when the throttle is cracked quickly.
As long as your fuel bowl levels are correctly set then you probably need to go with larger primary nozzles - 25's are tiny - probably only good for a very light car with a manual trans. Would also depend on how built your motor is and if manual/auto trans when sizing discharge nozzles to correct the off-idle stumble. On my 420HP-351W motor and C4 that's pushing a 3800# load down the road it needed 35 nozzles in the front. Tell us about your motor mods, trans and weight (including you in it, too).