Put six of them to bed for the winter.
312H, 520-8, 416H, 520H (X2), 312-8
Siphoned out most of gas then ran till empty.
Pulled battery.
These were barely ran all summer so I didn't bother doing oil changes etc.
Got the 520HC with the plow moved up and I will get it all checked out and ready for winter duty.
The 520 with the mower deck is still in service to grind up leaves for the next few weeks.