The teen sped up, driving more than 100km/h, on Te Ore Ore Rd and turning into Colombo Rd.
He continued on Colombo Rd, speeding and overtaking a vehicle, before turning into Herbert St.
Walker-Topia then rode through the Colombo Rd netball courts, back onto Colombo Rd, and led police through the Masterton CBD, at one point undertaking on the left-hand side for 20km. He eventually stalled on the public walkway, off Bentley St, and was arrested.
A blood alcohol test revealed a result of 81 milligrams of alcohol per 100 millilitres of blood, which exceeded both the youth and adult limit.
Walker-Topia has never held any form of driver licence.
In explanation the teen said he didn't want to stop because he did not want to lose his motorcycle.
Defence lawyer Jock Blathwayt said Walker-Topia had pleaded guilty at the first opportunity and no one was hurt by his driving.
Mr Blathwayt said he had enrolled in a course at Whaiora in case of any alcohol problems he may have.
Judge Broadmore said Walker-Topia was a young man with a good future and a good job.
"You obviously want to keep your job, and I want to support you in that, but this is just an appalling piece of driving," Judge Broadmore said.
He ordered Walker-Topia to pay a fine of $100, courts costs of $182 and medical expenses, for the blood alcohol test, which was more than $300.
He was also disqualified from driving for nine months.
