Final answer:
A cracked distributor rotor in a magneto can cause loss of ignition spark, inconsistent timing, and damage to the magneto.
Step-by-step explanation:
A cracked distributor rotor in a magneto can have several effects. One likely effect is a loss of ignition spark or weak spark, which can lead to engine misfires or hesitation. The cracked rotor may also cause inconsistent timing, resulting in poor engine performance or difficulty starting the engine. Additionally, the cracked rotor could cause damage to the magneto, requiring a replacement.