I just had a set of TWM 50 mm itbs installed on my itr motor and had them tuned. The idle is great and at 1000 rpm. It stays there until you press the pedal than it sticks to 1500 rpm and won't go any lower unless I manually pull the linkage closed. I have read about adding a third spring and that has cleared up most peoples issues. Where are you putting the spring? I would just like the idle to come down. Thanks.

 

Put a stronger spring so that it pulls the linkage shut. Put it anywhere where it does its job.