02 Honda CR 250 won't start

Nope your cylinder is not destroyed. Hopefully. This is weird cause my riding mate had the same exact problem on his 02 cr250. He did have a single ring vertex piston in it. The bike was hard to start and when it did get running, it ran like crap. I mean like bad. The thing was it very easy to kick over and no compression. When we took off the jug, we noticed that the ring actually seized in the groove. I inspected the cylinder it seemed fine with no gouges or burrs, we cleaned it up put in a new piston and the bike is running fine now. I know you live in arizona where it is dry but try to remember if you washed your bike before you put it away. You might of sucked some moisture in the cylinder, which caused the rings to corrode and seize. My recomendation is to buy an oem/wiseco double ring piston, stick that baby on and live happily ever after. Also check your crank while you have it off. Make sure no up and down movement.

Erik

Do the sides of the piston show signs of scuffing (4-corners)? It may have been a cold seizure from improper warm-up that caused the ring damage.