Practical Life span of modern scooters is probably combination of years and miles I am on 11th new one since 1990----my time/sign to get a new one is miles.....all but one have been ridden out to 40-50000 miles. think that adds up to over 400,000 miles on them. My first Burgman 400 went back to Suzuki at about 9,000 miles with porus engine cases, making excellent money at the time just went to dealer showroom and bought
Yamaha TMAX, probably the best running/handling/fun maxi scooter of all time, except complicated drive line,
Example on life of scooter, both my new SilverWing 600's were traded at near 50,000 miles, but I am sure they would have worked to 100,000 miles---I just did not want the hassle of getting to that point and maybe extra expense.