What movie has a highschool kid that invents an invisibility potion and helps his basketball team?

I can't remember much from this movie other than I watched it at a friends bday party roughly 1988-1990. I think a pigeon craps in his potion and it ends up making an invisibility potion. The kid uses it to help his basketball team and the downside of it is that their clothes don't become invisible so when it wears off, some hilarity and awkwardness ensues. Thanks