Thanks for the info!

I found a 180cc big bore kit on taobao for 360 CNY. No need to rebore, just bolt on a new cylinder/fit new piston. Maybe 180 is a bit too far.. maybe 150-160 is about right. Don't think the kits come with a jet though, that's another hassle. EFI.. yeah, probably a bit of a long shot :-)

Is the Yamaha really that much better? I'm a competent mechanic, but won't be carrying tools.

Jialing JH125. Looks like the 80s XL125, my first bike.

We fly in Macau, but might need to go to Hong Kong for the visa, trying to figure that out. Any suggestions for a attractive, or at least inexpensive town/city to stay nearby for some days while we get the bike and get set up for the trip? Really don't have much idea how China works. Don't speak any Mandarin unfortunately.