1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 10Get this manual

1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 10

1-5 GENERAL INFORMATION
PROPELLERS
An outboard motor is designed to develop its rated power within specified engine speed rangeThe maximum rated power delivered by the DF4050 models is shown belowRecommended full throttle speed range DF40 DF50 5200-5800min 5900-6500min

If the standard propeller fails to meet the above requirement, use another pitch propeller to hold the engine speed within the range specified abovePropeller selection chart