Adjust model's front wheels, not working without key (7)
I believe the answer is:
twiddle
'adjust' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for twiddle that I've seen before include "Finger idly" , "Tinker with" , "Idly rotate (one's thumbs?)" , "Play with and twist around" , "Turn in a purposeless way" .)