A cutter observed going to China, maybe (8)
I believe the answer is:
chainsaw
'a cutter' is the definition.
(I've seen this before)
'observed going to china maybe' is the wordplay.
'observed' becomes 'saw' (I've seen this before).
'going to' means one lot of letters go next to another.
'maybe' indicates an anagram.
'china' anagrammed gives 'chain'.
'saw' put after 'chain' is 'CHAINSAW'.
(Other definitions for chainsaw that I've seen before include "Tree-lopper's tool" , "Powered cutter" , "Power tool" , "powered device" , "woodcutter?" .)