Blame a little used and almost lost meaning of pore for the confusion between these two words.
A pore is a small opening, such as a skin’s pores. That makes it a noun. Pour means for something to flow rapidly and often continually, as in Pour me a glass of milk, please.
Usually the confusion regarding these two words occurs in the verb phrases pore over and pour over. Since pore typically is a noun, pour would appear to be the correct choice when writing a sentence such as He pored over the readout.
Pore, however, can be a verb meaning to meditate on. This verb is rarely used in modern times, but it is the source of the phrase pore over meaning to study closely.
Pour over only means to allow something to flow over another item, such as He poured milk over his cereal.