2009 Yamaha F40 Outboard Service Manual, Page 349Get this manual
MNT Outline
Maintenance
To ensure long product life, Yamaha strongly recommends the specified periodic check and maintenance to be performed according to the maintenance interval chart If replacement parts are necessary, use only genuine Yamaha parts of equivalent design and qualityAny parts of inferior quality may cause malfunction, and the resulting loss of control could endanger the operator and passengersYamaha genuine parts and accessories are available from Yamaha dealers The service intervals provided in the Maintenance Chart are based upon "typical" operating conditions that include speed variations, sufficient time for engine warm up and cool-down, medium to light load, and an average cruising speed in 3000 to 4000 rmin rangeIf your normal operating conditions are more intensive, more frequent servicing will be required, especially the engine oil and gear oil changesExamples of the intensive operation will be; wide-open-throttle, trolling or idling operations for extended period of time, carrying heavy loads, or frequent starting and stopping or shiftingIn most cases, the frequent maintenance pays off in increased engine life and greater owner satisfactionConsult Yamaha dealer for additional recommendations The maintenance cycle on these charts assume usage of 100 hours per year and regular flushing of the cooling water passagesMaintenance frequency should be adjusted when operating the engine under adverse conditions such as extended trolling Disassembly or repairs may be necessary depending on the outcome of maintenance checks Expendable or consumable parts and lubricants will lose their effectiveness over time and through normal usage regardless of the warranty period When operating in salt water, muddy, turbid (cloudy), or acidic water, the engine should be flushed with clean water after each use