Cusser
+1y
2. With the Weber, make sure that the accelerator cable is not bound, has a tiny bit of slack in it at idle.
1. Make sure that the return spring fully closes the throttle, I use a stronger spring than the chintzy one that was included in my kit. So check this#1.
3. Make sure that the choke is not set too rich.
4. Check/adjust your idle mixture screw adjustment (should be less than two full turns out from bottom position) and then the idle speed adjustment screw. Personally, I have left alone the so-called fast-idle stuff, but maybe in your case make sure its linkage isn't the cause.
5. My idle jets are 52 (passenger side) and 45 for secondary idle jet (driver side), check yours, stamped on them. Put a white towel underneath the area in case you drop them, and don't lose the sealing O-ring either. The jet pulls out of the part you unscrew.