Honda BF20A-BF25A, BF25D-BF30D Outboard Motors Shop Manual., Page 381Get this manual
Propeller Selection Chart Use the following table as the guide for propeller selectionTest run the outboard motor and check the maximum speedIf it is not the recommended maximum speed range shown the table, replace the propeller and test againAdjust bring the maximum speed the recommended speed range as neededPropeller size Model 6,000