Find large Mexican pancake flipping excellent at first (6)
'find' is the definition.
(locating is a kind of finding)
'large mexican pancake flipping excellent at first' is the wordplay.
'large' becomes 'l'.
'mexican pancake' becomes 'taco' (I've seen this before).
'flipping' shows that the letters should be reversed in order.
'at first' says to take the initial letters.
The first letter of 'excellent' is 'e'.
'taco' reversed gives 'ocat'.
(Other definitions for locate that I've seen before include "Find out where something is", "Set in a particular place", "Discover the place where something is", "site", "Pinpoint, find".)