AN UNKNOWN ACTOR scurries across a northern California beach. He's playing Jack Kerouac. But this supposedly athletic-looking Beatnik writer is thin and clumsy. He ends up ditching the beach after narrowly escaping a mound of dirt that plummets into the ocean.

This near disaster wasn't supposed to happen. It doesn't add anything to Kerouac, but the film crew probably didn't have time for a second take. There are a lot of scenes like this in Kerouac.

John Antonoli's documentary chronicles the life of a writer who has been compared to other Americans such as Hemingway, Fitzgerald and Whitman. And it handles the history well. But the actual film footage lags way behind an intriguing story.

The reconstructed scenes from Kerouac's life--which comprise about a third of the film, in addition to actual television excerpts and interviews with Kerouac's friends--resemble film clippings from Leonard Nimoy's In Search Of. These short pieces of film move slowly, the actor bears no resemblance to Jack Kerouac, and the scenes contain an inanity that we soon learn is unintentional. They seem like video filler for a predominantly oral presentation.

In addition to some dismal visuals, Kerouac deals with the controversial side of Jack Kerouac--the leader by default of the generation of writers and artists called the Beatniks--no better than have have recent print biographies.

Critics, social and literary, have scrutinized Kerouac for the questionable quality of his work (Truman Capote once said of Kerouac's prose, "this isn't writing, this is typewriting"), his political conservatism and his overt sexism. But the movie sheds little light, favorable or negative, on any of the juicier topics.

In what is likely good documentary form, Kerouac brings up all these issues without dwelling on any one in particular. The key issues surface--the author's Oedipal ties to his mother, his dabblings in Buddhism and his benzedrine-induced writing method, but although they're faithfully examined, Antonoli doesn't go beyond a cursory treatment of the straight facts.

Kerouac is a histo-biography, following the author from his working class beginnings in Lowell, Mass. to his eventual post-breakdown return to New England. Spliced in between are Kerouac's confrontations with the big city, his chaotic ventures through the U.S. that led to books like On The Road, and his encounters with members of the personality/literati circuit which included William Burroughs, Allen Ginsberg and Gregory Corso.

Arranged as a collage of video media, Kerouac is at its best during the television clips of the writer's appearance on shows like William F. Buckley's Firing Line and The Steve Allen Show.

MAYBE THE CAMERA CREW for Kerouac should have taken lessons from the makers of "Pull My Daisy" a 20-minute film which precedes Kerouac at the Orson Welles. Written and narrated by Kerouac in the late 1950s, "Pull My Daisy" is a humorous day-in-the-life tale of a few Beatnik writers during an afternoon and evening of goofing off.

"Pull My Daisy" gives a view of Kerouac from the inside, in his own jumbled form of narration. The feature film complements the shorter work because it looks at Kerouac from the outside--through the eyes of an objective biographer and through those of writers and artists who knew Kerouac best.

During interview segments, other Beatnik writers do not deny Kerouac's status as "King of the Beat Generation." Kerouac seems to be the hardest to pin down. He doesn't have the grisly panache of Burroughs or the self-conscious religiousity of Ginsberg. There is a certain instability, an un-disciplined heart to Kerouac's work and life.

In retrospect, the Beatnik's chaotic lifestyles and massive drug inhalations that shook some cultural foundations thirty years ago seem rather mainstream today. Even the lifetime chronicled in Kerouac has a definable pattern: Home-City-The Road-City-Home. Kerouac ends right where he began: as other Beats point out, the stabilty of home, his mother and his father is all he sought.

"He really wanted to be that old fart that was his father," says Lucien Carr, now a wire service editor who first met Kerouac at Columbia University.

The television clips are most effective because they reveal Kerouac's conservative character, both politically and socially. A scene from Buckley's Firing Line is particularly tragic. With merciless interviewing poise, Buckley casually questions the seriousness of Kerouac's writing and his tenuous connecting of religion and literature. Kerouac, obviously very drunk, answers Buckley on the air with a string of babblings on Buddhism. Ultimately, Kerouac makes a fool of himself, at the same time highlighting his own inability to fit in with the chic literati set.

While the story of Kerouac's life is a fascinating one, it is also much-told. While Kerouac is a meticulous documentary, it adds little to the spate of literary accounts of the author's life, many of which have been published recently. It is an opportunity sadly missed.