Crazy about Kelly? Completely bowled over! (7)
I believe the answer is:
stunned
'completely bowled over' is the definition.
'crazy about kelly?' is the wordplay.
'crazy' becomes 'nuts' (I've seen this before).
'about' is a reversal indicator.
'kelly?' becomes 'ned' (outlaw Ned Kelly).
'nuts' back-to-front is 'stun'.
'stun'+'ned'='STUNNED'
(Other definitions for stunned that I've seen before include "Stupefied" , "Amazed" , "Dazed; astounded" , "Knocked unconscious" , "Shocked" .)