Murphy then tried to light the newspapers but they were lying flat and did not ignite.
He then took the petrol hose from the pump and poured some petrol onto the newspapers, before lighting the petrol and running away.
The fire was seen by the Featherston Community Patrol and put out, before it caught hold of the pump.
The service station is the longtime workplace of Featherston fire chief Colin McKenna, who said they were not called out.
He said the community patrol just "jumped on it" to put out the fire.
Murphy's actions were caught on the station's CCTV cameras.
"We've got a pretty good video of it," said Mr McKenna.
Judge Barbara Morris said it was "clearly a grave offence".
"This could have been a disaster."
She told Murphy he was only being granted bail because of his age, but "your age will not save you if you breach your bail".
Murphy has been remanded on bail, with curfew, until sentencing on April 14, with reports ordered including psychological and drug and alcohol.
He will also reappear for plea on the other charges on March 24.
