With a solid victory in the Illinois primary tucked away, Ronald Reagan campaigned in New York City today as if President Carter were his only opponent.

Despite winning his seventh victory in eight primaries, Reagan refused to say he had clinched the GOP nomination over his remaining challengers, George Bush and Rep. John B. Anderson.

But as he spoke of his concerns for inner-city unemployment and the future of Israel, the former California governor sounded like a man whose focus had shifted almost entirely to the general election.

With all but a handful of the Illinois Republican precincts counted, Reagan had 48 percent of the vote, Anderson 37 percent, Bush 11 percent.

In the separate balloting for delegates, the latest unofficial compilation gave Reagan 39 delegates, Anderson 26, Crane 4, Bush 2, and 21 were uncommitted. Another 10 at-large delegates will be named later to complete the 102-member delegation.

On the basis of those figures, Reagan has 206 delegates overall, compared to 47 for Bush and 39 for Anderson, with 42 scattered among other candidates or uncommitted. Nomination at the Detroit convention requires 998 votes.

Despite the growing odds against their success, both Anderson and Bush renewed their vows today to stay in the contest with Reagan.

Bush told reporters before a private fund-raising luncheon in this city that they were "premature" to write off his chances, and said he had the finances to stay in the contest "a long, long time." Connecticut, which, like New York, holds its primary next Tuesday, will be the focus of Bush's campaigning for the rest of this week.

Anderson, campaigning in Wisconsin for its April 1 primary, said, "I simply cannot believe" the Republicans will nominate Reagan, whom former president Ford "said last week plainly cannot be elected president in November."

Rejecting the option of an independent candidacy for himself, Anderson said, "We are going to peel Ronald Reagan's fingers away from his grip on the nomination, one by one."

But if Reagan was worried about his remaining intraparty opposition, he did not show it as he tuned his campaign to the themes he would use in a general election

On Tuesday night, in New Haven, Conn., Reagan called himself "a Main Street Republican" who understood the problems of working people. Today, he traveled by commuter train from New Haven to New York for a day-long tour which included a visit to the New York Stock Exchange, tours of party headquarters in Brooklyn and Queens and meetings with Jewish leaders.

The day began with a speech to the Association for a Better New York in the Waldorf Astoria, where Reagan had held a news conference last November after announcing his presidential candidacy.

But the contrast between the two meetings was striking.

Last November, Reagan fumbled a question about federal aid to New York City, which he had opposed during the Ford administration, and wound up suggesting that New York City government had been wasteful and profligate. Today Reagan said that "we must follow the example of your city and make federal government more lean and efficient."

"However, this streamlining must not come at the expense of the poor and the disadvantaged," Reagan continued. "The Justice Department has estimated that across the nation, federal programs are beset with more than $50 billion in fraud alone. We should start cutting there."

Reagan also said the federal government should work with private industry in an effort to expand employment for inner-city youth.

"Further increasing employment must be a major priority for helping the cities," Reagan said. "Particularly, minority youth unemployment, which approaches 40 percent, must be remedied. Such unemployment is a scandal and a potential time bomb for all of society."

The heart of Reagan's economic proposal is his familiar call for the 30 percent, three-year income tax reduction embodied in the Kemp-Roth tax bill. Rep. Jack Kemp, a major congressional supporter of Reagan, sat at the former governor's table this morning as did former New York City mayor John Lindsay. Reagan heartily applauded when Lindsay was introduced.

Reagan has a long record of supporting Israel in foreign policy and he took every opportunity to demonstrate it today by criticizing the Carter administration support of a March 1 U.N. resolution decrying all Israeli settlements in occupied areas, including Jerusalem. Carter afterwards repudiated his support of the resolution, saying it was a mistake by the State Department.

Reagan, along with Carter's Democratic challenger, Sen. Edward M. Kennedy (Mass.), has been questioning whether the vote actually was the result of a mistake. Today Reagan said the resolution should be reversed and the Carter administration conduct "investigated," though he did not say by whom.

Reagan also took the opportunity posed by a question about the resolution at this morning's breakfast to reaffirm his overall support for Israel.

"The relationship with Israel is a two-way street in which we benefit greatly," Reagan said. "Israel is the only stable democracy left in the Middle East with a combat-ready military force that serves as a deterrent to further advances by the Soviet Union . . . If Israel were not there, we would have to be there with military forces."

Later, while campaigning in downtown Brooklyn, Reagan encountered a handful of protesters chanting, "Reagans wants war!" Reagan replied, "I'll tell you, you jokers. If I did want war, you're where i'd start it."

The dimensions of Reagan's Illinois victory are probably greater than today's numbers measure. While Reagan won 39 delegates outright, his Illinois campaign manager said at least eight "uncommitted" delegates had promised to support the winner of the popularity contest in their district, bringing Reagan's count up to 47. Totten has predicted that at least 80 of the 102 Illinois delegates will vote for Reagan in Detroit.

In the 16th Congressional District, which Anderson has represented for 20 years in the House, he barely edged out Reagan, whose boyhood home of Dixon is in the district. Unofficial returns gave Anderson a 46,817-to-44,076-vote lead over Reagan. The two men split the four delegates from the district.

The big Reagan win in the largest primary so far this year was achieved in the final 10 days before the voting, according to Reagan's pollster, Richard Wirthlin.

Wirthlin's pre-election surveys in Illinois showed Reagan and Anderson virtually even in the period between March 4, when Anderson finished a close second in Massachusetts and Vermont, and March 8, when Reagan won a smashing victory over Bush and John B. Connally in South Carolina.

Bush dropped two percentage points and Reagan gained seven points, all at Bush's expense, the following Tuesday, when he swept Alabama, Florida and Georgia.

But the signal event for Reagan in Illinois was the March 13 debate in Chicago among the four Republican candidates.

According to Wirthlin's data, 21 percent of the voters in the primary saw this debate. They judged Reagan the big winner, with 52 percent naming him as the victor, 14 percent naming Anderson, 8 percent Crane and 3 percent Bush.

"Bush was the big loser," Wirthlin said, even though Anderson was the target of criticism from the other three Republicans. "The debate reinforced the negatives people felt about him, and while Bush was forcing Anderson out of the middle ground, Reagan came over as an elder statesman."

In the days after the debate, Reagan gained eight points on a "personal thermometer" of people's feelings about a candidate, while Anderson remained static, at a lower level.

"Anderson's strong boost . . . came because people like the man, his clarity, his willingness to stand up for what he believes," Wirthlin said. "They bought the Anderson difference." But in the last 10 days of the campaign, as issues such as the [Anderson proposal for] a 50-cent-a-gallon gasoline tax became dominant on the Anderson side, he wasn't able to secure new votes, because his issues weren't helping him."

"The opposite thing happened to Reagan," Wirthlin said. "People knew where he stood on the issues. In the debate, however, they saw a different kind of man, a warm human being with a touch of humor. That's where Reagan picked up the extra votes that made this contest come out the way it did."

The Reagan managers are optimistic about an equally bright outcome in New York, predicting he will win a majority of the 123 delegates on Tuesday. nIn 1976, Reagan won only 20 of 154 delegates from Ford.

The voting in New York state is for delegates only, and there is no statewide presidential popularity contest. Reagan is assured of 30 delegates, because 15 Reagan delegates are running unopposed and another 15 unopposed but officially uncommitted delegates have said they support Reagan.

Roger Stone, the Reagan political director in New York, is also counting on the support of another 32 uncommitted and unopposed delegates which would give Reagan a total of 62 in that state.