Wow. I had no idea there were so many people who were as unhappy with, or disappointed with, the little China Gurl 2-strokes. I must now assume I've been very lucky so far.
A couple years ago I spent (I think) about $140 on mine. I had no illusions about it; I knew I wasn't buying a Morini. In the beginning I wasn't expecting much from it. When I was first running it, I was breaking it in so it smoked and was hard to start. I put an NGK plug in it, did some porting and tuning, and it ran great.
Since that time THIS SAME ENGINE was on the bike that was wrecked when I was hit by the truck. The steel bike frame was bent and cracked. The NT carburettor was cracked also; I think my leg was slammed against it. Other bike parts were later found to have taken enough damage to be beyond economical repair. (If you think this sounds bad, you should see my X-rays and my hospital bills. The bike and I suffered together.)
Once I was out of the hospital and moving around (still on crutches though, at this point) I looked the engine over, inside and out, and it seemed sound. So I bought a new carburettor, and mounted it on my present bike. It runs just as well there as it did before. I always check it thoroughly before each ride, as I do with the rest of the bike. I suppose I treat it like it's worth more than it really is. And it just takes the bike where I point it. I can only assume that I possess one of the best little HT 2-smokers around.
That said, 4-strokes are probably more efficient and pollute less. But I'm the wrong one to be able to say they are easier to maintain. Every one of my 4-stroke lawn mowers with Briggs engines were a pain in the butt, no matter how often I'd run them in the summer. I am meticulous with my maintenance, and each always had some little thing going wrong at some time or other. I guess the 2-strokers are just easier for me - fewer parts, less maintenance, greater reliability (for me anyway). Just easier and cheaper all across the board. Sure, they're disposable. They're so cheap that if something catastrophic goes wrong with one, you can just save a bit of cash and buy another. But, lawd hep me, here I am defending them. I'm pretty happy with mine.