A bill breezing through the House Judiciary Committee would tone down federal racketeering laws, and its critics are wondering why some lawmakers are so quick to support it, especially since it might let savings and loan scoundrels off more easily.

Entries in former national security aide Oliver L. North's notebooks tracking the Iran-contra scandal suggest why the bill might look even better for some members of Congress already predisposed to pass it.

If the teeth are taken out of the racketeering law, it could hamper one already shakey racketeering suit that has embarrassed some Iran-contra players on Capitol Hill.

Journalists Tony Avirgan and Martha Honey, through the Christic Institute, a Washington public interest law group, filed suit in 1986 against several major and minor Iran-contra figures.

Avirgan and Honey sued them personally under the Racketeer Influenced and Corrupt Organizations Act, known as RICO. The suit alleges that the Iran-contra supply operation amounted to organized crime involving drugs, guns and murder.

The claims revolve around a 1984 attempt to kill maverick Nicaraguan contra leader Eden Pastora at a news conference in Nicaragua. A man posing as a journalist carried a bomb into the news conference. Pastora survived, but four people were killed and Avirgan and Honey were among the injured.

At the time, Pastora was an outspoken critic of the main contra group and the Central Intelligence Agency had warned him to join those contras.

The Avirgan and Honey lawsuit is based on the strong racketeering law that Congress is about to dilute. Rep. Bill McCollum (R-Fla.) is a cosponsor of the changes and big supporter of applying them to suits already in the courts. He also stands to take some heat from the Avirgan and Honey lawsuit, now on appeal after being dismissed.

North's notebooks record that in 1985 McCollum and three other members of Congress were briefed by Reagan national security adviser Robert C. McFarlane on the status of the contras. They talked about a plan that included, "$25-$50 M. {million}, third country support and CIA intel {intelligence}." The notes could indicate that McCollum was aware of North's operation at a time when U.S. aid to the rebels was illegal. McCollum now claims the meeting was about a "lobbying effort" to restore aid to the contras. As a member of the committee that investigated North's operation, McCollum signed the minority finding that North did not break the law.

McCollum's top aide, Vaughn S. Forrest, has also been linked to the network that the Avirgan and Honey suit seeks to expose. In a deposition in that suit, one of North's couriers confirmed that Forrest knew John Hull, one of the defendants in the racketeering suit. Hull is an American who used the airstrips on his ranch in Costa Rica to supply the contras in the mid-1980s.

On the night that Pastora was bombed, Forrest was with Hull in Costa Rica. Hull faces murder charges in Costa Rica for his alleged role in the bombing. He now lives in Indiana while the United States and Costa Rica debate his extradition.

Forrest is not a defendant in the RICO lawsuit, but further exposure of his ties to the others would tarnish the reputation of his boss, McCollum.