More, the magazine that has followed an erratic course as a review of media journalism, has been purchased by a loyal subscriber who says he is prepared to spend a half-million dollars in the next year in pursuit of its founding goals.

James B. Adler, president of the Bethesda-based Congressional Information Service and a subscriber since More was founded in 1971, yesterday bought the magazine from Michael Kramer, the present publisher and editor, for a figure that will run over $100,000.

Alder says he wants to add a definite "Washington presence" to More's coverage although the main editorial office will remain in New York. He says he will keep the monthly magazine format and that J. Anthony Lukas and Richard Pollak, two of the original founders, have been enlisted as active advisers.

Asked why he was taking on a magazine that was losing money, Adler said:

"I have a very strong admiration for the impulse that led to More's founding . . . to be an honest media critic and hold the highest standards of journalism up to the profession and to be a forum for people in the profession."

More now has a circulation of slightly more than 21,000. Kramer, a 30-year-old alumnus of New York magazine, bought More in April, 1976. In 18 months, Kramer said, his investing group doubled circulation but lost nearly $400,000 and ran out of money before it could reach a break-even point.

Adler said yesterday that he "expects to be losing money for quite a while" but he thinks More can become a profitable enterprise without any "magic number" for circulation.

Adler said he plans to increase the editorial budget if not necessarily add to the staff.

"If there has been a continuing shortcoming of More," the new owner and constant reader observed, "it has been the failure to cover Washington adequately. In many ways this is the media capital of the world."

More has been plagued by bhsiness problems and deficits since its founding in 1971.

Robert Friedman, who has been More's managing editor, will stay on and take over the title of editor from Kramer.

Kramer said yesterday that he has had a "bundle of offers" and is taking a vacation before marking a decision. He wants to get back to writing, he added, but hasn't talked to Clay Felker, his old boss at New York magazine who now takes over Esquire magazine.

Pollak, who edited More for five-plus years from 1971, reached by phone from Massachusetts, said he's enthusiastic - "I want to feel enthusiastic" - about More's future.

"For the first time, More is being run by a man with business savvy," Pollak said. "We didn't have much when we owned it. And Jim (Adler) not only has a business track record but seems to have a commitment to the original idea."

Adler can take on a magazine losing money because he does have a track record in business. He is both president and chairman of Congressional Information service (CIS), which abstracts, retrieves and microfilms information from goverment publications for libraries.

Adler worked on the Harvard Crimson with Lukes and later was with NBC television. He has editorial and management experience in both broadcasting and publishing, including Publishers Weekly, Random House, and Putnam's. The CIS recently purchased the Greenwood Press, in Westport, Conn., which publishes scholarly volumes.

The business deal negotiated earlier this week was not a simple one-on-one transfer between Adler an Kramer. More Magazine, Inc., a wholly-owner subsidiary of CIS, bought the assets of CIS, bought the assets of Namequoit, Inc.

Namequoit happens to be the name of the summer sailing camp on Cape Cod that Kramer and his fellow investors attended as children.

Adler said yesterday that it was impossible to give a firm figure on what he paid for Namequoit's assets because part of it involves losses on unfilled subscriptions still to be determined. But he estimated it would be between $100,000 and $120,000. This would go to pay off Namequoit's liabilities.