Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Did it start ok with the choke before moving the needles? And, I'm sure you are a very experienced 400/4 owner but are you sure you are putting the choke lever in the correct position for ON/OFF, the arrow on the lever can be somewhat confusing (Don't ask me how I know that !!!!)
Jim (?) Have you adjusted idle speed screw to compensate anywhere along the line ? If you have, then there's a good chance that will have changed the 'fast idle' setting on the choke mechanism, and that maybe affecting your choke operation / warm up procedure. Worth checking to see if the cam on the choke lever (other side of the lever's pivot point at the top of #1 carb) is actually touching / moving the main throttle spindle.Would you mind telling me where you got your 38 idle jets please ? I'd be interested to try them on my 400 !Andy