I had a simaliar problem with a fresh rebuilt Carter Thermoquad rebuilt by Holly Corp. To get to the point if the pump bore is worn and has a smooth shiny surface you can get a week pump spray. I removed the top of carb and removed check valve plug at the bottom and shure enough the bore was shiny probably from the plating process they used when they rebuilt it.I took some polishing paper and roughed up the bore it should be like a freshly honed cylinder in a engine. This got rid of the stumble and provided a solid steam of fuel through the whole throttle range. Hope this helps. Bob Haag ----- Original Message ----- From: 2HsandaHeritage@xxxxxxxxxxx To: Chrysler 300 Club International Sent: Thursday, July 14, 2011 1:03 PM Subject: [Chrysler300] 413 stuttering Hi Group, My 62 Sport has a 413 with a single Carter AFB. The Carter AFB has recently been rebuilt. When starting from a dead stop the engine "stutters" for a few seconds and then performs like new. I had the same problem prior to having the AFB rebuilt. If I "hit the gas" harder at start up there is no "stutter" and the "stutter" seems to get slightly worse when the engine reaches operating temperature. The automatic choke appears to be operating correctly. Thanks in advance for your help, Doug Warrener Fair Oaks, CA [Non-text portions of this message have been removed] [Non-text portions of this message have been removed] ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx To unsubscribe from this group, send an email to bob@xxxxxxxxxxxxx or go to http://autos.groups.yahoo.com/group/Chrysler300/join and select the "Leave Group" button For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/search.htm#querylangYahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: Chrysler300-digest@xxxxxxxxxxxxxxx Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/