Over bagels and pickled herring, the two principal announced candidates for mayor of the District of Columbia accused each other yesterday of being overly intimate with their unannounced rival, incumbent Mayor Walter E. Washington.

Councilman-at-large Marion Barry and Council Chairman Sterling Tucker, addressing the Adas Israel Men's Club, found rough agreement on a wide range of subjects, including that of Mayor Washington's record, for which neither had a solitary kind word. But each man seemed to see himself as a consistent critic, and his opponent as an ally and confidant of the mayor.

Barry referred repeatedly to the "Washington-Tucker administration" and said, "This city is on the verge of becoming great, on the verge of going down. If you want four more years of what we have just had you ought to vote for one of the other candidates."

"In the last four years," Tucker replied, "Marion Barry has talked to Walter Washington more than I have. I don't know what they were talking about but whatever it was that's the kind of city you have."

"I am older than Marion, I am smarter . . . I am more able," said Tucker, who played up what he said were his proven managerial abilities as council chairman. "I could have organized that branch of government the way Mr. Barry organized the Board of Education . . . There was chaos in the school board when Mr. Barry was its president."

Barry, in turn, emphasized his efforts to reduce property taxes and to provide various kinds of relief for the elderly, who were well represented in the audience. He proposed that the city provide a once-a-month escort service to help elderly recipients of government aid get their checks cashed safely.

The audience, which had gathered for breakfast at the Adas Israel Congregation at Connecticut and Porter Street NW, did not display much open enthusiasm for either speaker.

One questioner attacked the financial management of Pride, Inc., the neighborhood self-help group Barry helped form after the 1968 riots, and wondered if Barry would handle the city's tax moneys more responsibily.The same questioner wanted to know why Tucker had put his children in private school.

"My record with Pride is one of proud accomplishment as far as I'm concerned," said Barry. "We did something that no one was willing to do . . . we put young people in leadership positions."

"I think my record in support of public schools is very clear," said Tucker. As a politician, Tucker explained, he would work as hard as he could to improve the public schools, and "I work as hard as I can as a parent to provide the best education I can for my children."

Neither Tucker nor Barry seemed anxious to discuss the case of indicted mayoral aide Joseph Yeldell. "I'm glad there's still such a thing as 'no comment'" Tucker said.

Both candidates agreed to the proposition that a majority of D.C. Government department heads are incompetent. "We have some dedicated D.C. Government employees," Barry conceded. "My wife is one of them so I have to say that, but we have far too many doing far too little . . . Two-thirds of the present department heads . . . are totally incompetent, and under a Barry administration, you can rest assured they will not be there long."

Tucker said he would not top at two-thirds, the incompetents are more numerous than that, he claimed. Barry replied that he would name his two-thirds as the campaign progresses, and the first name, he said, would be that of Lorenzo Jacobs, director of Housing and Commu be that of Lorenzo Jacobs, director of Housing and Community Development.