I've had a Toro TimeCutter 42" MyRide (75747) for a couple years now. Since the start of this mowing season, it will start initially but turn off if I get off the seat, regardless of the PTO switch being disengaged. This was negative an issue until this year. Once it is stopped, it won't restart. It's a no click, no start too so I'm guesing something electrical. It's almost like the safety feature for the PTO switch is misinterpreting something.
If I leave it alone long enough, it will eventually restart but it can take a while. I'm actually waiting for it to hopefully restart currently but it's been 20-30 minutes and still no luck so far.