Marshawn Lynch -- I Was A Loud Mouth Once ... Back in High School [Video]

Marshawn Lynch has been taking heat for BARELY saying a word at the Super Bowl media events in NY this week ... but years before he clammed up, the guy gave one of the GREATEST football soundbites of all time.

It all went down after Marshawn's Oakland Tech High School beat up on Skyline High back in '04 ... that's when Lynch -- who had just scored a MONSTER rushing TD for the win -- erupted on camera after the game.

There was raw emotion ... there was pure happiness ... there was a promise to treat his linemen to a fancy dinner at Sizzler.