Kick-start on your bike (4,3)
I believe the answer is:
buzz off
'on your bike' is the definition.
(both can be used to tell someone to go away)
'kick-start' is the wordplay.
'kick' becomes 'buzz' (both can mean a feeling of excitement).
'start' becomes 'off' (as in 'from the off').
'buzz'+'off'='BUZZ OFF'
(Other definitions for buzz off that I've seen before include "Scram, get lost" , "Go away (like a swarm?)" , "Go away (like a 17?)" , "leave hurriedly" , "As a bee might - get lost!" .)