A state district court jury here yesterday sentenced two self-acknowledged revolutionary communists to five years on probation for inciting a 1978 riot of Mexican-American youths.

Travis Morales, 26, and Mara Youngdahl, 30, also were fined $5,000 and $4,000, respectively. A third defendant, Thomas Hirschi, 25, was fined $1,000 on misdemeanor riot charges.

Morales, a steelworker and a former medical student, called the sentences "outrageous."

But prosecutors, who has asked for the maximum sentence, 20-year prison terms for Morales and Youngdahl, were clearly disappointed by the sentences.

Defense attorney Jim Larson said, "We're overjoyed that the sentences were probated," adding that he was "pleasantly surprised at the outcome."

The trial stemmed from a May 7, 1978, riot in Moody Park on Houston's largely Mexican-American north side, when teen-agers at a flesta marking the traditional Mexican Cinco de Mayo holiday attacked police.

The riot and disturbances at a nearby housing project the next night came near the first anniversary of the death of Joe Campos Torres, a Mexican-American who drowned while in the custody of Houston police officers.

The disturbances resulted in about $500,000 in property damage. The defendants described themselves as supporters, but not members, of the Revolutionary Communist Youth Brigade, a Maoist group.

Their political beliefs were a central issue in the trial. Larson and another defense attorney, Dennis Riordan, both of San Francisco, argued that the defendants had been put on trial as scapegoats by community leaders who refused to acknowledge grass-roots resentment of the police.

In April 1978, a federal judge sentenced three former officers to one year in prison and five years on probation in the Torres case after a state court jury gave two of the officers one year of probation.