When the Amateur Sports Act of 1978 reaches President Carter's desk, he should sign it immediately, as the final indication that Americans are willing to spend 14 cents each for nonprofessional athletics.

For about six weeks every four years - or during the summer and winter Olympics - the country cares deeply about amateur sports. The remainder of the time is spent wondering how the East Germans could possibly beat our swimmers or Cuba win so many boxing and track championships or the Soviets a basketball gold medal.

The thoughts linger briefly, however, and soon we again are heavily subsidizing such as the Redskins, the Red Wings and Red Sox, devoting almost daily attention to Maryland's football and basketball teams when its best athlete is a hurdler, Renaldo Nehemiah.

Part of the reason for professional dominance is that so much of amateur sports has been amateurish, disorganized and improperly staffed, full of internal strife and often at odds with the very people they are supposed to help - the athletes.

The Amateur Sports Act offers clear and useful reforms, and also the promise of helping the casual jogger as well as the Olympian marathoner. Already, Congress had authorized up to $16 million to implement the act. If the President signs, the bill, it will be the first significant victory for amateurs in decades.

For years, the primary source of Olympic athletes has been the school systems, usually the colleges. Yet nearly every collegiate cost-cutting measure has hurt the Olympic sports. Before football scholarships were mildly snipped, track and swimming aid was slashed.

This infusion of money still would not alter a basic fact about amateur sports: the athletes with the most time and money to spend win. What it would do is give more youngsters a chance at orderly competition and a place to train.

Who could find harm with that as a national athletic priority? America should not be underwriting athletic robots whose mission in life is gymnastics, biathlon or the 1,500-meter run. But it ought to give every future Edwin Moses hope.

You may recall Moses. He is arguably the best athlete in the world at the moment, the fellow who won the 400-meter hurdles in Montreal in record time, then pranced about the track with the runner-up, another American, Mike Shine.

If government had interfered with sport, selected certain athletes and honed them for years, Moses might have stepped off the track years ago. He was a mediocre 120-yard high-hurdler and a mediocre quarter-miler who, without benefit of training facilities at Morehouse College in Atlanta, still found a comfortable event.

And ran farther than anyone could possibly imagine.

According to the executive director of the U.S. Olympic Committee, Don Miller, part of the $16 million would be used to restructure amateur sports and part used to finance training centers throughout the country to help Moses-like athletes in various events.

The American selection of an amateur sports hero mirrors its lack of devotion to amateur sport. Bruce Jenner is the primary example.

Jenner now is a modest televison personality and cereal salesman, rich by most American standards. He got there by winning the decathlon at Montreal, highlights of which are featured in his cereal commercials.

You may have noticed that in the background of some of those Olympic scenes are empty seats. That is because hardly anyone cared enough to watch all 10 of his events, even though the decathlon had been highly publicized for months.

The surest way to empty a stadium of track devotees is to schedule a decathlon. Yet the American Olympic winner, a man mediocre in 10 events that cause no passion within track and field, becomes rich and famous.

Still, Jenner suffered in obscurity while in pursuit of the decathlon title, realizing fully the rewards victory and a world record would bring.

If the directions Jenner and Moses took after Montreal were different, the paths they used to get there were similar. Neither came from affluent backgrounds, yet both managed to succeed against subsidized athletes from other countries.

The Amateur Sports Act simply gives more athletes more of a chance to follow Jenner and Moses. And the sports medicine aspects of the bill will benefit every sport at every level. There seem to be more than enough congressional checks.

American amateur sport has needed direction and cohesion. This bill provides it. American amateur athletes, from youngsters through Olympians and especially those beyond collegiate competition, could use better facilities and medical research. This one-time grant is a models one, but necessary.