Ingenious Inventor is Hero of a Changing Revolution. A poor peasant who drifted to Hanoi, Vua Lop has a rags-to-riches tale that would serve as a business school case study on how to be an entrepreneur, Vietnamese-style. VIETNAMESE ENTREPRENEUR

THE man who comes close to being the Thomas Edison of Vietnam has a word to the wise. Be careful if you invent a better mousetrap. The world may beat a path to your door. But the Communist Party may spring a trap of its own.

Three times Nguyen Van Chan has been branded an ``enemy of the state,'' and he was jailed twice after reaping profits from his own inventions. Today he is a legend in Vietnam, the little guy who endured the slings and arrows of a party that, until recently, valued brawn over brains and toil over talent.

A survivor of a shift in ideology, Mr. Chan has become a hero of the revolution - that is, the latest version of the Vietnamese revolution, the one calling for ``renovation'' by using the best of capitalism to build communism.

Few Vietnamese know Chan by his real name. Rather, he is called ``Vua Lop,'' the Tire King. In a country that regards bicycle tires as a necessity, Vua Lop is the mother of invention. Like him, his tires can't be beat.

A poor peasant who drifted to Hanoi, Vua Lop has a rags-to-riches tale that would serve as a business school case study on how to be an entrepreneur, Vietnamese-style.

His days of ingenuity began with plastic fountain pens. One day in 1969, his son asked him for a pen. He examined the construction of the pen he bought at the state store. ``There was no big deal to the parts, nothing needed for national defense,'' he said. ``Anyone could make it, only no one was trying.''

After a year of experiments, he created a better pen with recycled scrap plastic. When he sought an official permit for production, he was denied. He was told to join a collective, but he declined.

Though he refused to reveal his industrial secrets, he was finally granted a permit. Some months later, when customers began to stand in line to buy his better pens - and after his income shot up to more than 20 times the average - his small workshop was raided by local authorities.

``I just made goods for the people,'' Vua Lop says. ``But some officials have hostile hearts and were jealous.''

Hanoi's city court sentenced him to 30 months in jail for ``illegal'' business. In 1972, a judge released Vua Lop, but he was barred from making pens.

During the next two years, he experimented to formulate a new type of glue for repairing rubber tires. Customers again lined up, and again he earned too much money. The police arrested him, demanding that he reveal his secret formula. Then they threw him in jail for three months.

By then, he was accustomed to injustice. ``Some officials put a limit on being rich. But they don't put a limit on being poor.''

Once again a free man, he began to experiment with recycling old rubber into new tires. By 1984, he was selling up to 2,000 bicycle tires a year, charging higher than average prices because his tires survived well on Hanoi's rough streets.

Like clockwork, the police showed up one day, accusing him of stealing state materials. But the real reason for the arrest was more obvious. They demanded he divulge his secret of recycling rubber - or go to jail. Vua Lop had not even revealed the secret to his sons.

Rather than face a prison cell again, he went underground for six months, trying to appeal his case. Eventually, he was reprieved but still had to reveal his secrets. And his equipment and workshop were confiscated.

By 1986, Vietnam's Communist Party was changing its tune. Free markets and private enterprise were given a longer leash. The press was told to bird-dog anyone practicing ``unrealistic'' Marxism-Leninism. In early 1988, Vua Lop became an instant celebrity when his saga of woe was written up in a Hanoi newspaper.

``He's not an isolated case,'' says Xuan Cong, the former editor of Labor newspaper and a Trade Union official. ``It's just that this one was exposed.''

Another case was that of a fisherman repressed after inventing a new way to catch a high-priced fish. Or there was the closing of a Haiphong factory which devised a new way to make high-quality reproductions of antique ceramics.

The party now appreciates the role of risk-taking investors. ``If we don't fear foreign investors, why should we fear our own little capitalists?'' says Le Dang Doanh, a government economic adviser.

In October, the party issued a new policy on royalties and set up a patent center. ``We welcome rich people, if they carry out their trade honestly,'' Nguyen Van Linh, the new party chief, said.

In Ho Chi Minh City, the leading newspaper started a new column this year entitled ``Brains to the Market,'' giving advice on how to make new goods and open a private business.

In June, Vua Lop was allowed to go back into tire production. In November, with his fame spread far and wide, he exhibited at a trade exhibit in Hanoi. One day, he was paid an unusual visit by Vo Van Kiet, deputy premier and a Politburo member. Their picture was taken together, and Mr. Kiet congratulated him for his work on behalf of the revolution.