Bruce Pollard, the director of Red Baron, argued that because Aprilia bikes were produced only in small numbers, bringing parts in from Italy could be a lengthy process.
He said total sales of Aprilia motorcycles in New Zealand were only 82 last year.
It was not unusual for there to be up to six weeks delay in getting motorcycle parts, even from the major manufacturers, Pollard told the tribunal.
For that reason, he claimed McLaren was not entitled to reject the motorcycle.
The Tribunal disagreed and said in its determination that Red Baron had failed to repair McLaren's motorcycle within a reasonable time.
"The Tribunal thinks, on balance, that Mr McLaren rejected the motorcycle within a reasonable time of the date of supply having regard to the fact that the motorcycle was new when it was supplied to him, had only been ridden 2,678kms, and was first returned to Red Baron to be repaired on 11 January 2013."
McLaren was entitled to reject the motorcycle and was entitled to a full refund of his purchase price of $8,445, the tribunal said.
Red Baron finally repaired the bike on April 8, three months after it was brought in.