The PTO lever engages the mower blades.
BTW, here's a forum you might enjoy reading, now that you have your L100 JD:
http://forums2.gardenweb.com/forums/tractor/

rOn

"Pete" wrote in message
...
I just bought the L100 John Deere Lawn Tractor and the manual isn't the
best
(IMHO).
Can anyone here explain what the PTO lever does exactly? The manual talks
about engaging it and disengaging it without really explaining what it is.

Same for the RIO button.

Any help would be greatly appreciated.
thanks in advance