Here in the SF Bay area a kart like that sells for ~$1,500 – 1,800. If you can and have the mechanical skills, remove the cylinder and rock the rod from the small end and measure the movement. Verify that it’s within the CR80 manual limits to check bottom end health. I’m comfortable purchasing used engines only after verifying the condition, or, plan and budget to rebuild the engine before puting the kart on the track. Belts and braces…