It may well be a truth, but it's not the whole truth - we've all sidestepped the fact there's more then just the "china girl" kits, overlooked the truth that there's other options, including prefabricated motorized bicycles of all types that would require little more then an interest in riding and a wallet to match the demands.
Electric, four stroke & two strokes prebuilt and simple kits still better then bargain basement - there's plenty of quality out there that would meet his wants;
good shocks so i can ride off road.
something that wont rattle the motor off
I want fast durable and strong
somewhat legal
He never said "cheap" and I can't even blame him for "can't get my China girl started" as they're renowned for having issues, as most were quick to point out. How about suggesting his interests exclude such problematic cheap kits, that if he can't wrench & wants all the above that spending the pennies for quality will go a long way, which incidentally doesn't have to exclude motorized bicycles for motorcycles?
A more valid warning would be price, equally an issue with motorcycles, even more so if you're not mechanically inclined or experienced.
Then there's the real dilemma... even if you can wrench or it's just a matter of time as you're willing to learn, is a "china girl" still the most valid option when discussing "wont rattle the motor off, fast durable and strong"? Heck I love the things but when all's done and said it's either a cheap, low quality kit motor or it's become an expensive, time consuming highly modified custom engine that still may or may not fit those wants. To get a china girl to be like that often costs as much or more then another type of motor entirely, one already built to be such.
The china girls are a great introduction to mechanics, if that's your primary interest. They're cheap & fun, if that's all you want. If you're already an experienced mechanic they're a good platform for experimentation - but aside from those interests they're often a false economy purchase, you'll spend a dollar to save a dime trying to get it to be anything other then it is, a cheap copy of a inefficient design outdated by at least seventy years.
If you want to learn, it will take some time. If you just want to ride, the "china girls" are perhaps not your best bet. If you just want a different bicycle to put a "china girl" in, I don't know why this thread's gone the way it has lol