Yamaha VX250B Owner's Manual

E3-5EMU01788Run the engine under load (in gear with apropeller installed) as follows.1) First 10 minutes:Run the engine at the lowest possiblespeed. A fast idle in neutral is best.2) Next 50 minutes:Do not exceed half throttle (approxi-mately 3,000 r/min). Vary engine speedoccasionally. If you have an easy-plan-ing boat, accelerate at full throttle ontoplane, then immediately reduce thethrottle to 3,000 r/min or less.3) Second hour:Accelerate at full throttle onto plane,then reduce engine speed to three-quarter throttle (approximately 4,000r/min). Vary engine speed occasionally.Run at full throttle for one minute, thenallow about 10 minutes of operation atthree-quarter throttle or less to let theengine cool.4) Third through tenth hours:Avoid operating at full throttle for morethan 5 minutes at a time. Let the enginecool between full-throttle runs. Varyengine speed occasionally. Avoid oper-ating the engine at 2,000 r/min andbelow for more than 1 hour at a time.5) After the first 10 hours:Operate the engine normally. Use onlystraight gasoline in the fuel tank. The oilinjection system provides proper lubri-cation for normal operation.