Maintenance59perform a maintenance procedure, have aYamaha dealer or other qualified mechan-ic do the work.The procedures involve disassemblingthe motor and exposing dangerous parts.To reduce the risk of injury from moving,hot, or electrical parts: Turn off the engine and keep the key(s)and engine shut-off cord (lanyard) withyou when you perform maintenance un-less otherwise specified. The power trim and tilt switches operateeven when the ignition key is off. Keeppeople away from the switches whenev-er working around the motor. When themotor is tilted, keep away from the areaunder it or between it and the clampbracket. Be sure no one is in this areabefore operating the power trim and tiltmechanism. Allow the engine to cool before handlinghot parts or fluids. Always completely reassemble the mo-tor before operation.EMU28511Replacement partsIf replacement parts are necessary, use onlygenuine Yamaha parts or parts of equivalentdesign and quality. Any part of inferior qualitymay malfunction, and the resulting loss ofcontrol could endanger the operator and pas-sengers. Yamaha genuine parts and acces-sories are available from your Yamahadealer.EMU34151Severe operating conditionsSevere operating conditions involve one ormore of the following types of operation on aregular basis: Operating continuously at or near maxi-mum engine speed (rpm) for many hours Operating continuously at a low enginespeed (rpm) for many hours Operating without sufficient time for engineto warm up and cool down Frequent quick acceleration and decelera-tion Frequent shifting Frequently starting and stopping the en-gine(s) Operation that fluctuates often betweenlight and heavy cargo loadsOutboard motors operating under any ofthese above conditions require more frequentmaintenance. Yamaha recommends that youdo this service twice as often as specified inthe maintenance chart. For example, if a par-ticular service should be done at 50 hours, doit instead at 25 hours. This will help preventmore rapid deterioration of engine compo-nents.