You've got a sticky valve guide, and the pushrod is getting bent by trying to force the valve open against some major resistance. It might be possible to work some carburetor cleaner down the valve guide from the top, but it's more likely you'll need to pull the head and clean up all the valve stems with a wire buffer, plus do a cleanup on the inside of the guides. If one is sticking, others are probably close to having the same problem. Bite the bullet and do a valve job.
Jerry
