I have a 1985 Agri Power 5000 aka Zetor 5011. It has a mechanical clutch and I need to adjust travel on the pedal. I have a manual, but it doesn't address it.
Generally you adjust so you have 3/4 to an inch of free play before the pedal actually starts to put pressure on the clutch. From there you can fine tune to personal preference but you should always have some free play to ensure you're not slipping the clutch.