When the gang eavesdrops on Alfalfa and Darla from the bridge, the distance between the tin can and Alfalfa's head changes between shots.
When Alfalfa and Darla are in the clubhouse, Alfalfa's drink repeatedly switches from hand to hand between shots.
Scene shows the gang has already put together parts of the derby car including the bird cage on the front as the radiator. The next scene shows Porky and Buckwheat just finding the bird cage in the trash.
The writing on the note that Porky and Buckwheat get the in the beginning, is different in different views.
In the very first scene when Spanky is writing the message, a shot of him shows he is holding the black crayon in his right hand as he's folding the paper. When it cuts to the next shot, Spanky is now holding a clothespin in the same hand and the black crayon is now sitting on the stairs next to his right foot.
Waldo's dog, a Doberman, is named "Fifi" and referred to by Waldo as a "good girl" and "she", respectively. However, when the dog jumps on Alfalfa and gets back into Waldo's car, it's very clear the dog is male.
Before Darla kisses Alfalfa in the boat, she flattens down his
cowlick (at 10:53 on the DVD) but in the next shot (from behind Alfalfa at 10:56) it is still standing up. It then *pings* back up in the next shot (at around 59 mins). The cowlick is only visible at 10:56 in Full Frame format remastered from the original "spherical" (non-anamorphic) 35 mm negatives and is not visible in the Wide Screen format (which does not show the full height of the negatives). It is not a goof by the film makers, but rather by those who released the film in Full Frame format.
In the scene where Darla has just met the "oily" boy, she says
"what a hunk!", and her friend says "he's smoother than a baby's bottom". The third little girl is mouthing her line.
When sitting in the race car, Darla looks momentarily at the camera. Jane can be seen silently mouthing Mary Ann's line.
At the beginning, when Spanky is sending the emergency meeting note to gather the gang, we can see it's already been written before he writes it.
During the go-cart race, when The Blur 2 activates the "spin cycle" the go-cart stops and the camera shows a shot from the top before they spin around. On the asphalt you can see the tire marks from previous shots.
(at around 10 mins) While the gang is on the bridge watching Darla and Alfalfa in the boat, Buckwheat says, "It's worse than I thought." Standing behind him you can see Uh-huh (the character that is only supposed to say "Uh-huh") mouthing the word "thought".
When Darla says "Oh, Alfalfa, you're a sweetie pooh", her lips
aren't moving (at 10:53 on the DVD as she flattens Alfalfa's cow lick).
The receptionist of The Boys Club says "And stay out!" when Spanky goes in to hide from Butch and Woim, but his mouth does not move when he appears.
When Porky and Buckwheat are running up the hill to the race, Buckwheat's lips aren't moving when he talks, yet the audio can still be heard.
At the end of the race when Alfalfa is lying on the front of the go-cart trying to tie Darla's handkerchief back to the trophy, his lips aren't moving when he is yelling.
When Butch and Woim start the rocket boosters in the race, Butch complains that Woim put them in backwards, and they fly backwards down the road. If you look closely, when Butch says "you idiot" his lips aren't moving.
In the scene where Darla and Waldo catch Alfalfa getting out of the pool at Waldo's mansion, there are several shots of the dog barking at Alfalfa. Behind the dog is a piece of the miniature mansion set used in that scene.
Waldo refers to his dad's car as a Bentley when it is really a Rolls Royce.