FITECH EFI 600 Basic and Command center intall with pics, factory tank

[Transam461]

In reality, they both SHOULD adjust by just turning the front screw, since the linkage on these throttlebodys are setup for 1-1 operation of the primary and secondary butterflies , instead of being progressive, but it's a possibility for the linkage to still have a slight movement of the primary butterflies before it starts to move the secondaries, just simply from the little play that's in the linkage rods, or some may not be adjusted exactly perfect. Ours seemed to have just a tiny bit of play, it wasn't very much at all though. That's the reason I always recommend to adjust the primary and secondary screws evenly.... I hope this helps

Brian