Cannondale ATV Owner's Manual page 68

Starting a warm engine - (MC500 or MC1000)
When starting an engine after it has reached operating
temperature, do NOT open the throttle while operating the
starter motor. This will make starting very difficult and
possibly foul the spark plug.
66
When reading this manual, remember:
WARNING
Indicates a potential hazard
that COULD result in serious
injury or death.