Join Date: Jul 2006
Location: Lehigh Acres, FL
Jets and Carbs
Let's talk jetting and carbs for bit. Have been reading til I'm cross eyed about this.
My 406, with specs as in signature has what I would call a stumble when I am idling along at slow speed in lower gears, like you would be down a local street. It occurs when you attempt to ease down on the throttle and speed up just a tad. The motor seems like it doesn't want to accelerate at all until you give it even more gas, then it jerks ahead.
Jets are as I bought the Quick Fuel Drag 750 carb, 74s in front, 76s in back, 3.5 power valves front and back, idle vacuum-7.
Question is, is this stumble caused by not enough jetting in the primaries or what. Car is pretty streetable over all, just have this issue low down. With the Quik Fuel, I can adjust idle speed on both primaries and secondaries, but not sure how to proceed. Timing is set at 20 degrees initial and the rest all in by 3000, as I recall.
Opinions and suggestions appreciated.
69 RS coupe, 4.11 Richmond gears, Muncie 4-speed, Dart SHP 406, 11:1, 4340 H-beam rods and crank. SRP forged pistons, Milodon 7-qt pan, Dart single plane and 215cc Pro1 alum heads, Comp XR300HR cam and roller rockers, Howard hydraulic roller lifters, Hooker 1 3/4" Super Comps, Quick Fuel 750 carb