Honda BF5A Owner's Manual page 35

Shear pin change
A shear pin is used to protect the propeller and drive mechanism from
damage when the propeller strikes an obstruction.,
1. Remove the cotter pin, the propeller cap, and the propeller.
2. Remove the broken shear pin and replace it with a new one.
3. Install the propeller, then install the propeller cap finger tight.
4. Install a new cotter pin, and spread the ends as shown in the illustration.
PROPELLER CAP
/
COTTER PIN
COTTER PIN
SHEAR PIN
SPARE SHEAR PINS
AND COTTER PINS
33