seized engine

NB: I'm not an engine person. My son has a 1994 yfs200. The engine seized. He removed the top end (cylinder). Nothing seems damaged there. The piston won't move and it won't crank over. The worst-case scenario is it needs a complete engine rebuild. ~$600 just for the kit--for starters. What...

I was riding my 2002 blaster I was riding in 6th when the tires locked up the motor stopped and it came to a stop I tried to kick it over and the kick start wouldn’t budge so I kicked it as hard as I could and it turned over I kicked it 3 more times and it started right up but sounded wired so I...