A 17-year-old Kalihi youth who was killed Saturday night when his speeding moped ran a stop sign was a Farrington High School senior who loved mopeds, his family said yesterday.

Gerald Baltazar was not wearing a helmet when he hit a station wagon at the intersection of Lowrey and O'ahu avenues and Mänoa Road at 10:05 p.m. Saturday.

Baltazar's parents are Ernesto and Divina Baltazar, and he has two brothers and two sisters, his sister, Mary, 23, said yesterday.

According to a police report: the youth who was killed was heading west in the east-bound lane of O'ahu Avenue, riding next to another moped that was also traveling west, but in the west-bound lane.

Witnesses yesterday said that there were three or four boys on mopeds riding together when the fatal accident occurred. A man whose home is at the intersection said the other moped riders left the scene before police arrived. He did not want his name used out of consideration for the Baltazar family.

A neighborhood woman, who also asked that her name not be used, said the Baltazar family told her one of the other moped riders called the family and told them what had happened before they rode away.

A 26-year-old man in the Subaru station wagon was driving west on Lowrey at the time of the accident, police said. The man reached the intersection of Lowrey and Mänoa Road, stopped at the stop sign and then attempted to turn left onto Mänoa Road.

At that point, the mopeds ran a stop sign and went into the intersection, police said. Baltazar's bike crashed into the station wagon.

Baltazar was thrown from his moped; he was pronounced dead at The Queen's Medical Center Saturday night.

No one else was injured.

Police said speed was a factor.

About 16 of Baltazar's relatives and friends, including his father and aunt, Delia Sarmiento of Kaimukí, were at the scene yesterday, trying to find out what they could about the circumstances. They left a memorial of flowers.

Mary Baltazar, who is an accounting student at Phoen-ix University and works part time as a bookeeper, said Gerald loved mopeds.

"He was into mopeds," she said yesterday, wiping away tears. "It was his hobby. Whenever he got back from school or his job at Burger King, he would ride or work on motorcycles."

She said she did not know who he was riding with Saturday night. Asked if Gerald ever raced motorcycles, she said: "He liked to do tricks, but he never said to me that he raced. I have never seen him racing."

As the family and friends put out a vase of flowers across the street, she said:

"I just want to say to all those teenagers out there on mopeds: Please be careful, because look what happened to my brother. I wouldn't want that to happen to you guys. Please learn from this."