"Treat me as fair as possible," WBA light heavyweight champion Michael Spinks implored Philadelphia reporters after he was pulled over for allegedly running a red light, arrested early yesterday, charged with illegal possession of a stolen gun and arraigned later in the morning.

"I'm not worried what will happen, I'm worried this will tarnish my image. It's a big minus," said Spinks, released on recognizance.

Spinks, about to begin training for his 175-pound title unification bout with Dwight Muhammad Qawi March 4, was pursued 25 blocks, police said, before they got him to stop his Mercedes. At his feet, they said, was a .45-caliber revolver with six spent cartridges.

Spinks said he hadn't realized the flashers to his rear were directed at him. The gun, he said, was "a keepsake" given him on a visit to Montreal after the 1976 Olympics (police said it had been stolen in Canada in 1975). He said he fired it in a field Jan. 1, to celebrate "making it to the new year," then forgot it . . .

Leland Spinks, 20, in the car with Michael, was not charged. But in Detroit, their brother Leon Spinks, heavyweight ex-champion who has had several brushes with the law, mostly involving vehicles, is accused by an attorney of "bobbing and weaving," ducking notice of a $1 million lawsuit over the crash of Spinks' Cadillac and a taxi Dec. 23, 1981.