Twin Cities-based Polaris Industries has been hit with its 12th recall of the year, this time for a fire risk involving one of its off-road recreational vehicle models.

Polaris is contacting the owners of roughly 6,300 ACE 325 vehicles after it received six reports of exhaust pipes cracking, the Consumer Protection Safety Commission said last week.

In two of those incidents, the CPSC continued, the heat from the crack melted the seat. There have been no fires and no injuries reported, the agency added.

The recall covers model years 2014 through 2016, and they were sold from December 2014 through July 2017 for about $7,500.

Consumers should contact Polaris directly on weekdays at 1-800-765-2747 from 7 a.m. to 7 p.m. for more information or online at www.polaris.com, then click on “off road safety recalls” near the bottom of the home page.

The Medina-based company’s 11th recall of 2017, issued in August, involved throttle-switch problems on 2,800 Scrambler XP 1000 vehicles.

Counting last week’s recall, Medina-based Polaris has now recalled more than 425,000 machines in the past 2 1/2 years because of mechanical or fire problems.

On top of the recalls, the National Highway Traffic Safety Administration opened an investigation last month into Polaris’ Slingshot motorcycles after a man in Michigan was killed while operating the three-wheeled vehicle.

The man was partly ejected in a head-on crash despite having on his seat belt. His family has contended that the seat belt retractor exploded during the crash, allowing the restraint to release.