Looking for Friendship in a Time Too Full for Love : THE MYSTERIES OF PITTSBURGH <i> by Michael Chabon (William Morrow: $16.95; 297 pp.)</i>

Early on in Michael Chabon’s remarkable, if flawed, first novel, the recently de-girlfriended narrator, Art Bechstein, is standing on a street corner one evening in the company of his new-found friend, the suspiciously good-looking and convivial Arthur Lecomte. Suddenly, Abdullah, one of Lecomte’s cohorts pulls up in a convertible Fiat, and Art finds himself sitting on the trunk, wind in his hair, as they whip through the night streets of Pittsburgh.

“The people in the cars that managed to pull alongside the Fiat,” Art muses, “gave me the same shake of the head and roll of the eyes that I myself had often given other young drunks in fast cars. I decided not to think about them, which proved to be a simple thing, and stared into the wind, and into the steady flow of streetlights.”

Much of the tone of “The Mysteries of Pittsburgh” is taken from this one scene: Bechstein’s simply choosing not to notice, not to think of how he spends his summer after graduation, the months of June, July and August swimming past in sweltering heat and cool nights while he watches lights and lives fast.

That tone might make one think of “Pittsburgh” as just another in the increasingly long line of Bret/Tama/Jay books being put out by the publishing world’s corral of jaded young writers, and in many ways it is. There is the obligatory coolness to all things, exemplified by Lecomte and “all the hip places he had been, the perfect manner of the life he lived, his sarcastic brilliance, his hard amusement.” There are the long nights at parties coupled with the intense nostalgia for a time when we were all just kids in sneakers talking on porch steps while the sun failed in the West. There is even the repressed memory of Bechstein’s dead mother, a fact which, astonishingly like McInerney’s first book, seems to give impetus to Bechstein’s lost-boy attitude.

There is, too, the unbridled booze, the unbridled family structure, and, of course, the unbridled sex. But it’s the issue of sex here that makes Chabon’s book different. Not that the sex per se is different--his renderings, in fact, are rather tame--but the manner in which sex becomes Bechstein’s reference point, his identity through a summer spent first in a few rather sex-filled weeks with the quasi-beautiful Phlox, a woman a little too too, “from her too blue eyes to the too red stockings she wore . . . as though she had studied American notions of beauty from some great distance and had come all this way only to find she had overdone the details: a debutante from another planet.”

Then comes August, and sex with Lecomte: “ ‘Are you in full capacity of your faculties?’ ” Lecomte asks of Art, who has been ducking and evading the feelings he’s been having for him all summer. “ ‘I can’t be certain; no,’ ” says Bechstein. Lecomte’s reply: “ ‘Well, it’s about time,’ he said. He pinched my earlobe. ‘Let’s go exhaust all the possibilities.’ ”

Exhaust they do, but Bechstein still seesaws between Phlox and Arthur, never quite sure which to choose over the other, both wanting him with enough unspent energy as to “make love” to him anytime, anywhere: on doorsteps, in study carrels. Even in bed.

But what keeps this book from falling into the abyss of the Lost Young Americans oeuvre is Chabon’s willingness to delve deeper, his ambition to find out precisely what love is, whether homosexual or heterosexual. “I find in myself no ready trace of Phlox,” Bechstein recollects, apparently years later, in the astonishingly moving final pages of the book, “no habit, hobby, fashion, or phrase, and for a long time I wondered if I had loved her or not. But as I have found that I may fall completely in love with a man--kiss, weep, give gifts--I have also discovered the trace a woman leaves, that Phlox left, and it is better than a man’s.”

His decision finally to embrace his homosexuality, then, isn’t anything more than accommodating himself to a world in which love appears too easily, too frequently: “In any case, it is not love, but friendship, that truly eludes you,” Art realizes, love having become diluted and ineffectual from its overuse.

The flaws here are many: superfluous characters like Jane Bellwether, who is given so much attention in the early pages of the book that we suppose she might be Art’s love interest, only to have her summarily dropped half-way through; Cleveland, Jane’s paramour and Art’s terminally straight rich-boy-turned-biker friend, a perpetual jokester and tough guy with a golden heart; Abdullah and Lurch and Feldman and Riri, even the unnecessary if hilarious diversion of three pit bulls named Manny, Moe and Jack thrown in for some doggy-sex fun.

In one of the more puzzling twists here, Bechstein realizes he must accompany Cleveland, a lowly grunt in the Pittsburgh underworld, on a whirlwind tour of his collection route, Bechstein’s father being, quite coincidentally, a high-level, low-profile accountant for the Mafia.

And in the climactic scene of the book, a Cagney-esque “top o’ the world, Ma” denouement in which Cleveland is chased by police until he looms larger than life atop a factory building, we see the author’s hand guiding us along, leading us toward some armchair psychologist’s point: Cleveland is at once everything his dad never was and everything his dad is right now--only a gangster. There is, too, that nagging, annoying my-mother-is-dead-don’t-talk-to-me undercurrent that seems to want to take on more presence in the book, but doesn’t.

But what makes this book--and Chabon--worth our attention is the intent. Contrary to the tone set by that ride on the trunk of the Fiat, Chabon has chosen not merely to record all the ills of an oversexed, overindulged generation with nowhere to go but to bed or to a bar; he has chosen to explore, to enter this world and try to find what makes it work, why love and friendship choose to visit some, deny others. This first novel’s flaws pale when one looks past them to the heart here, the compassion for characters simply trying to wade through a world too filled with itself to let real love surface, breathe, and take us in.