spark off vs set off

spark off and set off both are verbs.

Word	Noun	Adjective	Verb	Adverb
spark off	No	No	Yes	No
set off	No	No	Yes	No

As verbs, spark off and set off are synonyms defined as:

Other synonyms of spark off include activate, actuate, spark, touch off, trigger, trigger off, trip.

spark off (verb)	set off (verb)
put in motion or move to act	cause to burst with a violent release of energy
	set in motion or cause to begin
	direct attention to, as if by means of contrast
	provoke or stir up
	put in motion or move to act
	depart for someplace
	make up for