Live PTO Explanation
There is a lot of confusion about what a Live PTO is and isn't. A live PTO, normally, has a 2 stage clutch. You can depress the clutch 1/2 way in and the transmission will stop but the PTO will continue to spin under a load (not just free spin). If you depress the clutch all the way the PTO will stop also. This is very useful when mowing because you can stop, change gears, back up, etc while the mower continues to receive power.
If the PTO is not "live" it will stop receiving power every time the clutch pedal is depressed. Because the PTO is always directly connected to the transmission you will need an over run clutch if you use a high momentum implement like a mower.
Almost none of the Yanmar models have a live PTO. There are those, however, that are making an argument that the PowerShift Yanmar transmission is the sort of the same as a live PTO because you can keep the pto spinning while changing gears and changing directions.
Some newer tractors have what is called an independent PTO which is usually controlled by an electric switch. You can turn the PTO on and off using the switch and the position of the clutch pedal has no effect on the PTO.