A high school kid becomes increasingly obsessed with cracking an enigmatic waffle house owner.

After an enigmatic waffle house owner refuses to acknowledge his sign is misspelled, an entrepreneurial high school kid conspired with his best friend to make a profit on his secret recipe.

My plot kind of changed a little over the months, so is this more concrete?

I agree, adding the inciting incident to the logline will help, such as:
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"After discovering the local waffle house owner's having an affair with his mother, an angry teen vows to take him down."
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(Obviously your inciting incident will be different)

Hope that helped, good luck with this!

What I'm going for is the kid has a key flaw that has manifested itself strongly in the mean and unhappy Waffle House owner. The kid can't figure out what why he's so interested in this guy though. Hmm, let me see how I can restructure this loglinge. Thanks so much!