My first belt lasted over 25,000 miles. I put on a new one and the variator froze, almost welded itself together 1,500 miles after that. If the 250 uses the same variator set up? I would change out the belt, the 2 pulley halfs and the bushing/sleeve (the outer pully slides in and out on) at or around 20,000 miles or so. Or change to a malossi variator and maybe clutch. Just a suggestion.