Dixon ZTR 3000 Series Operator's Manual page 21

OPERATION INSTRUCTIONS
STARTING INSTRUCTIONS:
1. Move throttle control to "Choke" position if engine is cold, full throttle if warm.
2. Insert ignition key and turn to "Start" position. When engine starts, release
ignition key. Key will return to "Run" position.
3. Move throttle from "Choke" to desired speed position.
NOTE:
Page 18
While mowing, "blade(s) engaged", throttle control should be set to the
MAXIMUM or wide open setting to insure adequate cooling of the
engine and to maintain mower deck blade speed.
Engine cannot be restarted when blade is engaged or the parking blade
is off.
Safety switches stop engine when operator leaves seat while mower
blade is engaged.
Always turn engine off when leaving mower.
DO NOT rely on safety switches.