They last awhile. I had an 1998 formula z 583. Had 17600 km’s on it when I sold it. Guy who bought it emailed me it was best used sled he ever bought after putting on another 3000 km’s that winter. A few years later motor went with 27000 km’s on odometer. He sent me another email with pics and said motor should have been rebuilt, before I sold sled. I was like that was pretty cheap riding for you to double mileage on 2700 sled. It never ends.