So let me provide you with a little reality check to help you keep things in perspective... I am not a complete idiot, but I certainly can screw things up like one. And this is my story.
First off let me say, a stock Stella, while not the peppiest, is pretty dialed and will perform for years and years. There is something to be said about not upjetting, getting new exhaust, etc. Hindsite... 20/20... you know the routine.
With that said, When I hit around 1200 or so miles on my 08, I started futzing. I deblued, put on a Sito+ and changed the jetting based on recommendations to match a stock PX150.
That is when the hell we hear breaks loose did. I could not for the life of me get the jetting right. I dug around online and got all kinds of advice good and bad. I dismantled my carb no less than 5 times, replaced gaskets, checked and rechecked fuel lines, etc. This went on for 2 months give or take.
After an hour long call with someone online, I went back to the settings on my mix screw that had worked the best for me. My plug looked good and according to my best knowledge, was running a tad rich. I had a small leak and had to replace the carb gasket again, but the gasket I was sent had no hole for the oil delivery system. I normally inspect/overlay the gaskets to compare before I install them, but this time I was so fed up I just put it on.
And then I went for a short ride. I didn't get far when she started losing power and then died. I stopped, got off and looked and there was 2T oil all over the place out behind the carb, in the airbox, on the ground, etc. The words WTF and OFS came to mind. I checked the carb and it seemed to be down tight and to spec, so I fiddled with the mix screw, and she started. So I took it easy on the way home and she then started making an odd sound and died again. I was not far from home, I coasted to a stop then pushed her.
When I got to the house, I pulled the carb and realized what had happened. The gasket without the right oil hole had kept the fuel from mixing with oil and therefore she was running mega lean and then oil-less minus any residual. I checked the autolube gearing, the oil line, and put the old gasket back on. I went out quite a bit on the mix screw to make her really rich to try and quickly get some oil back in, and got her running. I didnt rev or futz too much until she ran for a few minutes. Then started getting the mix screw back into the happy position. She ran, but was making a strange noise which slowly went away. I knew it could be a sign of a problem but I was so stupidly happy to just have her working, I let it go, but kept her a tad rich just in case.
I rode her for a week or so like this and she ran better than she ever had since I started messing with her.
And then... My world came crashing down.
Last Wednesday, I was on my way to work. I got off the bridge and onto Riverside where it goes to 50MPH and just as I passed 40, I heard a loud sound and a rattle and then she died. I coasted to a place to pull over off the main road and knew I had really done it this time. I didn't even have to have anyone look at it to know I had blown something in the engine. She was seized up good and I was at fault for letting it happen.
I had her towed to the local shop where I was told the engine was toast. And that it would be $1000 to rebuild the engine or $1500 to put in a new one, plus time for jetting it properly. OUCH.
I decided to have her towed home and pull the engine myself and do the replacement engine myself to save some money. Plus, I felt like I got myself into this mess, I should try and fix it myself.
Piston head blues:


After removal of the reed valve:

Chunks of piston resting on the edge there.
Down in the main block:

Those are chunks of the piston you see in there.
I have not yet pulled the engine and cracked the case, but am expecting the worst.
Oddly, esp odd after seeing the piston... the cylinder looks unharmed!

Oh, and I decided if I was going to blow my savings on a motor, I would blow it in style. I placed an order for a brand new Piaggio P200 crate motor, complete with autolube and electric start. Which is that falls thru, I will get ASC to just build me one, sans the autolube and electric start.