I now have checked (almost) all episodes and found another great episode of boys running, wearing track shorts (looking like swim shorts) pic 1 in s1e20. White, black, light blue and colorful (purple, yellow black striped). Almost as good as the previous post.
Some shirtless in swim shorts and/or board shorts in the long episode “Skippy The Movie” (unknown episode #, obviously a special or pilot). One boy in light blue swim shorts and at least one older teen boy in black shorts (rear views only). Probably some more. Also some shirtless and wet like 10 yo main character Simon James as mentioned in s1e22.
Main entry (Soccer) still rating “only” 9 at