It'll be a long while. I like my Yager GT 200i, so I'll probably run it 'til the wheels fall off or I lay it over so badly that it'll never be the same again.
I've got a Tank Urban Racer 150 DE that was maintained in a similar fashion. Despite the fact that it's the cheapest of cheap Chinese junk, it's got almost 10,000 miles on it and still runs OK most of the time. It tends to intermittently cut out after being ridden for a while. I think it's electrical (as EVERYTHING suddenly cuts out... engine, lights, dashboard, everything), but after all the headaches that bike's given me, I think I'll just give it to the first enterprising youngster I find who demonstrates that he can turn a wrench well enough to keep it running. I fixed most of the things wrong with it from the factory, but after a while, you just have to let bad bikes go.
It's too bad, too. That bike was low-slung and light. It'd get up and move with traffic no problem, I could flick it from one lane to the next at speed easily, and it rode great... there was no dramatic loss of traction if you went into a corner too fast (as I often did, just for the grin-factor). You could feel the tires slipping, but they never completely went into a skid. You just hold on, back off the throttle a bit, let it slip a bit, lean it til you hear it start scraping, and it'd get you through the turn. The setup on that bike inspired confidence when you rode.
I find the Kymco Yager GT 200i to have a higher center of gravity, it's harder to flick it into another lane, and it doesn't do as well when leaned over in a turn. But, that may be because it's faster than the old bike by a good 20 mph, and heavier, so it's got greater G-forces to deal with.
Still, the Kymco Yager GT 200i is a much better bike. It's great to be able to keep up with interstate traffic.