This city, you might have noticed, is not your garden variety American city.

But its fiscal mess, which plunged it into default last week, is only one distinction. Another is that Cleveland simply does not do all the things that most other American cities do.

It does not operate its own school system or welfare program. It does not run its zoo, its transit system, its major parks, its hospital or its big ssewer system.

So why is it in so much financial trouble?

"Because for years it has improised by using financial gimmickry," Finance Director Joseph G. Tegreene said in an interview today.

He noted that in the early 1970s Cleveland sold off its assets-such as its big storm sewers (acting under a court order) and its transit system-and used the proceeds to pay day-to-day operating expenses.

This year Mayor Dennis J. Kucinich proposed selling $6 million worth of city property, including land leased by the Chessie railroad and property in the suburb of Warrensville. But the city council, which has feuded with the mayor for the entire 13 months he has held office, refused to sanction the sale.

For years city politicians, in another dubious fiscal practice, have tapped the proceeds from note and bond sales to pay for current expenses.

This year Tegreene hired the accounting firm of Ernst & Ernst to see just how far into the hole the city had gone with its commingling of funds. The firm found that as of the end of last year, the city treasury was down $38 million and that by this past June, it was lacking $52 million. By the end of this month, the figure is expected to be $41 million.

Finally, Cleveland, like many other cities, has postponed paying bills from year to year. Tegreene said that after taking office, he discovered he had to pay the city's 1976-1977 obligation to Cuyahoga County for the Justice Center here out of 1978 operating funds.

He also had to use current operating money to pay the federal government for 1976 and 1977 expenses incurred under the Comprehensive Emplyment and Training Act's public service jobs program.

"I now have to defer to 1979 our part of 1978 Justice Center expenses and 1978 CETA expenses," he said adding:

"This cannot continue. It's got to stop. It has brought the city to colloapse in the bond market." Tegreene was refering to Cleveland's inability to pay $14 million in notes held by six local banks and its low credit ratings which prevented it from borrowing in the nation's money markets.

Tegreene said the city can no longer rely on "one-shot gimmicks" such as the sale of assets to correct its imbalance of revenue and expenses. "We need recurring revenue sources," he said, citing a Kucinich proposal to raise the city's 1 percent i percent income tax to 1.5 percent.

If approved by the council, which is expected to consider it Friday, and then by the voters, the measure would add $33 million a year to city coffers.

In 1970, then-Mayor Carl Stokes proposed raising the tax to 1.8 percent. As an incentive, he cut property taxes. But the voters surprised him and turned down the income tax increase, and Cleveland was then stuck with a reduced property tax rate. The loss has cost the city some $180 million so far. And Cleveland voters have had two additional chances this decade to raise their local income taxes. Each time they have said no.