Failure to restart when hot is the main symptom of vapor lock. The hot engine and lack of flowing fuel vaporizes what should have remained as a liquid. It' happens more redily if you are still using a winter fuel blend. Restarting will be difficult.
On those engines the breather is on the other side of the engine, no need to remove the carb/tank to get to it. As Star said, the next time it won’t restart, check for spark. Common problem on those older engines is a coil that develops a hot short or hot open, which would mean replacing the coil if you find no spark.
