Brian Moore, a Ward 2 community activist and health care consultant, declared his candidacy for District mayor yesterday, charging Mayor Marion Barry with running a morally bankrupt political machine that has "besmirched" the city's home rule government.

Moore, an independent who drew about 18,500 votes in his losing bid for an at-large seat on the City Council in 1984, proposed to run a low-cost campaign in which campaign contributions would be limited to no more than $100 each, and promised that, if elected, he would serve for only one term.

Moore, citing "a growing number of administrative failures and continuing series of scandals," said the Barry administration has been "catastrophic" for the city.

"He has embarrassed not just the city, but more importantly, his actions have besmirched our new District government under home rule," he told a crowd of 75 supporters at the St. Vincent de Paul Church, 14 M St. SE. "The District government is in its political infancy and it desperately needs the right kind of leadership to pave the way for its future mayors and for our jurisdiction's total autonomy."

Moore, 42, is the third formally declared mayoral candidate, joining former school board member Mattie Taylor and sex entrepreneur Dennis Sobin. The mayor, who is expected to run for a third term, has said he will announce his plans in late April or early May. A Barry campaign finance committee filed its organization papers with the Office of Campaign Finance Feb. 25 and has raised more than $200,000, according to Barry.

Moore, who is white, told the audience that he believes race will not be a factor in the campaign.

"Washingtonians will choose the person, no matter what his or her color is, who can forcefully correct these serious managerial problems and provide strong moral leadership to the District's citizens," he said.

A former Peace Corps worker, the candidate proposed to experiment with a private takeover of the city's public housing, asserting that if management of selected housing complexes improves under private ownership he would advocate turning the entire system over to private sector management.

Moore said he supports reorganizing the city's health services, turning over D.C. General Hospital, Medicaid administration, St. Elizabeths Hospital and the city's mental health services to a national health care corporation. A District health department would monitor the system to ensure compliance with law and professional standards.

The candidate, professing a desire to "strike a blow for the cause of the unskilled and uneducated black teen-agers and young adult population," said he would promote new blue-collar light industries in the city, which, he said, would provide more jobs than are provided currently through the District's job training programs.

Among Moore's proposals are a decentralized police department with more substations, augmented by a 20,000-member corps of volunteer auxiliary police, limited "federal state" autonomy for the District that would include two votes in the House of Representatives and local control over judge selection and budget approval, and a city-funded consumer lobby to promote consumer interests in city government.