Hey, don't knock a JB Weld piston fix - I got stuck in Glamis with a hole burnt thru my piston, and that got me back to my truck, several miles away over lots of gnarly desert.
There was zero chance of me pushing my bike back through that stuff, and zero chance of getting a truck into the area my bike was at.
It sure didn't want to idle, but I made it back. Since I didn't have a file handy, I had to grind the top of the piston down on a rock to get the melted crap off. I had to wait until it got toward evening for the air temp to be cool enough not to burn it up again. I am SO glad I had a headlight on that bike.