At the beginning of "Mischief," Jonathan (Doug McKeon) is cruising in Pop's Studebaker, lamenting his unrequited longing for Marilyn (Kelly Preston), when who should appear but the beloved herself, strolling down Main Street, U.S.A., in a snug cashmere sweater. Jonathan ogles her, narrowly misses an oncoming Ford and drives off the road, knocking over a fire hydrant.

And awaaaaaaaay we go!

The lovesick swain befriends Gene (Chris Nash), the Valvoline Valentino who, offering such chestnuts as "Girls don't put out in Studebakers," sends the signals from the dugout, plotting Jonathan's strategy to get to first, second and third bases, and ultimately home (also known as "all the way"). Before the seventh-inning stretch, Gene himself has gone aflutter for Bunny (Catherine Mary Stewart), who is the chosen of the resident rich kid and bully (D.W. Brown).

They make love in cars and fall out of cars. They make love at home and are discovered by parents. They get drunk and confide their innermost secrets. They fight with the richies. They learn that love is more than sex. They crash their cars. And they do this while Chuck Berry, Fats Domino and Elvis Presley play on the sound track.

"Mischief," in other words, is echt teen sex comedy, hitting its marks in the way a skilled carpenter drives home his millionth nail. Even the deviations from the formula, like the movie's sweet, naive tone, are only predictable extensions of the formula. Screenwriter and executive producer Noel Black began his career with prizes at Cannes and critical acclaim, disappeared for a while, and returned, with "Private School," as a purveyor of virginity jokes. He's a born-again schlockmeister. But hackdom is something you're born to; Black is obviously too smart for this sort of thing, and his movie has the stifling aura of an idle exercise, as if Einstein trained his powers on a rousing round of cribbage.

Oh, well, at least the girls are pretty.

Sometimes you wonder if George Lucas, who started all of this with his classic "American Graffiti," ever lies awake in the wee hours in his northern California hideout, a latter-day Frankenstein ruing his creation. I'm here to tell ya, George, it ain't your fault. Mischief, at area theaters, is rated R and contains nudity and profanity.