The Genie S-85 cherry picker, worth about $150,000, was severely damaged during the fire at Willow Park in March.

Kieran Williams-Dale returned to the Wodonga Magistrates Court on Thursday.

He entered guilty pleas to two charges, including arson, during a brief hearing before magistrate Stella Stuthridge. 

The matter will next be heard in the County Court on September 7.

The court heard Williams-Dale, who appeared wearing a blue shirt, will continue to report to police three days a week.

But a condition banning the Stevenson Street resident from leaving the property at night has been removed.

The magistrates court had previously been told he had avoided touching the boom lift so his fingerprints would not be left at the scene.

He used a T-shirt to lift a cover, and a fuel line was identified and severed before being lit.

He ran from the scene and the machine was destroyed.

The court had heard Williams-Dale went to an associate’s house and bragged about what he had done.

Detective Sergeant Graeme Simpfendorfer told the court in March the teenager’s actions had escalated.

“The behaviour now is at that critical end,” he said.

There were underlying mental health issues, the detective said, and Williams-Dale's mother had been unable to get him help. 

Thursday's court hearing was told a mental health care plan had been formulated.