NSW boy critical after trail bike smash

An 11-year-old boy remains in critical condition in hospital as police search for a trail bike rider who struck him on the NSW Central Coast.

The Niagara Park boy was hit on Sunday afternoon on Parsons Road, Lisarow, and has since been airlifted to The Children's Hospital in Westmead.

He was placed in an induced coma with skull and facial fractures.

A hospital spokesperson said on Monday the boy was in a critical but stable condition.

An anonymous tip off on Monday enabled police to track down a helmet and the unregistered orange and black KTM trail bike, seen leaving the scene, which was found at the front of a home.

The offender was still on the run, a police spokeswoman said.

Witnesses told police the male rider did not stop to offer assistance after the crash.

A family friend, Mark, told 2GB radio the boy is out of an induced coma and is communicating with doctors and his parents.

"He's got a long way to go," he said on Monday.

Police are urging anyone who witnessed the incident to contact Crime Stoppers.