They also affect handling. But on a 25 it's not like a huge deal or anything.<br /><br />Mercury was recently sued over this issue. The plaintiff basically wanted all motors to have one for safety. The Perry Mason moment came in court when a video was shown of a mannequin arm being struck by a propeller. The arm was badly gashed but still intact. The other arm was introduced to a motor with a prop guard. Sliced and diced! Without the propguard, a blade hitting bone will push the limb away. With a propguard, it's held nicely in place so that it's like going thru a food processor.![]()