My PT425 can run at any time, with or without the operator in the seat. There are only two pedals(no, not a bicycle), one for forward and one for reverse. There are no brakes. There is no neutral. There is no range selector. There is a parking brake, but it does not have to be on to start or run. The only time I leave the seat while it is running is in extremely cold temperatures when it needs to warm up the hydraulics for a few minutes. I bury the snowplow in the dirt, set the brake, step on the forward, then reverse pedals to make sure the pin-in-slot parking brake is actually working, then carefully exit paying particular attention to the foot pedals and my large winter boots. Otherwise, I set and test the parking brake and shut it off every time I get off, no matter what. And I always use the seatbelt, even if I'm only moving it a few feet. The possible costs of engine wear, starter wear, battery wear, etc... is insignificant to me. It only takes a couple of seconds to be safe and possibly a lifetime to recover from a mistake that could have been avoided.
With that said, I suppose I could remain sitting on the tractor while it warms up. Its only 5 minutes VS a stay in the hospital.
I understand why some people need to get off the tractor while it is running... especially in AG situations, like operating a conveyor, grain elevator(or whatever they are called), hammer mill, etc... and it has to be done. There is no way around it other than to buy a dedicated power plant for each piece of machinery. The important thing is to be familiar with your machine and always practice as safe operating techniques as possible and never take shortcuts to save a little time. Be careful out there. /forums/images/graemlins/smile.gif