The film begins with a charming scene featuring a bakery truck cruising down the street, while Beaver and Wally ride together on Wally's bicycle, delivering morning newspapers. In an amusing display, Beaver flings the papers into the air with both hands—one lands smack in wet cement, others awkwardly decorate two roofs, a few find their home in a dog’s mouth, one makes a splash in a birdbath, while another hilariously perches on a cat, one gets caught in a man's leaf-vacuum nozzle, and yet another right onto a painter's head. This chaotic moment culminates in the leaf vacuum exploding, showering dirt into the bakery truck’s driver side window, triggering a series of sticky mishaps with the pies. Sincerely apologetic, Beaver and Wally take off on their bicycle.
Eager for a shiny new bike he spotted in a store window, Beaver is skeptical that Ward and June would purchase it for him. Amidst his uncertainty, Eddie Haskell gives him a crafty tip: by charming Ward into signing him up for football, his chances of getting the gift for his birthday would significantly improve. Taking the advice, Beaver joins the football team and although he struggles with being much smaller than his teammates, he endures the rigorous practices. Striving to distance himself from childlike comfort, he even declines to let Ward read him a bedtime story and kiss him goodnight, all while brimming with anticipation for his first game. Ward, hopeful about his son's decision to play football, is devastated when Beaver's game ends in disaster; he mistakenly throws the ball to a rival who he once considered a friend from summer camp. When Beaver celebrates his birthday, his wishes are granted with the much-coveted bike and a computer gifted by his great aunt.
On the very first day back to school, just five days later, Ward and June instruct Wally to keep an eye on Beaver as he settles into the routine of riding his new bike. Beaver’s new teacher, Miss Landers, is kind-hearted, making the transition more enjoyable. After school, Eddie encourages Wally to head to the soda shop, keen to show off his flirting skills to Karen. Not wanting Beaver in tow, Wally leaves him at the bike rack with a promise to return. While polishing his newly acquired bike, a mischievous teenager approaches and offers to demonstrate some thrilling bike tricks. Eager to learn, Beaver agrees, only to have the boy ride off with his new possession.
At the soda shop, Karen shows interest in Wally, much to Eddie's dismay. As they leave, the unfortunate news of Beaver's stolen bike hits them, prompting Wally and Eddie to embark on a frantic search, but their efforts yield no results. That evening at dinner, Beaver and Wally attempt to hide the reality of the missing bike. When Ward uncovers the truth, his frustration is aimed not just at Beaver, but more so at Wally for failing to keep an eye on him. This leads to a clash between Beaver and Wally in their bedroom, resulting in Beaver's expensive computer being thrown out the window. Wally’s attempt to save it ends in a break, leading to a catastrophic crash onto the ground—this infuriates Ward, leading him to ground both boys entirely.
Following their grounding, Beaver neglects football practice to hit the books, while Wally spends time with Karen, who soon breaks it off to reconnect with her former boyfriend, Kyle. One day, when Beaver ventures into the city, he narrowly escapes an accident with a truck. In an ironic twist of fate, he encounters the very boy who stole his bike. The boy, who happens to be Kyle's younger brother, proposes a challenge: climb a gigantic coffee mug atop the local café to reclaim his bike. In an unfortunate turn, Beaver falls inside the mug and struggles to escape. Thankfully, the fire department and Ward come to the rescue, with Ward realizing perhaps he's putting too much pressure on Beaver. After discovering Beaver has been skipping practice, he offers him the choice to quit, but Beaver resolves to stay with the team.
During his final game, Beaver seizes the opportunity, ultimately making a touchdown while in pursuit of his stolen bike. At the Mayfield Festival, their paths cross again, leading to a heated chase. Kyle accidently trips Beaver, assisting his brother in escaping. Wally, upset by the unfairness, retaliates by pushing Kyle into a tub of fudge. The situation culminates with Karen, put off by Kyle's bullying behavior, choosing to be with Wally instead. In a clever move, Beaver cleverly uses a concession stand to block the boy’s escape, leading to a spectacular fall into a judges' table of pies. This delightful chaos results in Beaver finally recovering his bicycle. Back home, Ward notices Beaver polishing the bike and, with a sense of concern for safety, suggests that it should remain indoors. He lovingly obliges Beaver's request to read him a bedtime story, wrapping up the heartwarming adventure.
