Here's a pic of my ride Taken in 09/19 She now has over 37,500 miles on her.
2005 NE-5 Whizzer Motorbike - 4 stroke
The secret to long engine life is to Fix It before it breaks.
Up Grade it, then Up Grade it again. Maintenance and more Maintenance then more Maintenance.
You'll have almost no extra maintenance beyond regular bicycle maintenance with a 2 stroke China girl. 4 strokes with soft parts are a different nightmare, aka satisfaction of overcoming a challenge lol.