Yamaha 15F Owner's Manual

Also see for 15F: Owner's manual Owner's manual Owner's manual Owner's manual Owner's manual

Operation25bow up, the boat may have a greater tenden-cy to steer to one side or the other. Compen-sate for this as you steer. The trim tab canalso be adjusted to help offset this effect.When the bow of the boat is down, it is easierto accelerate from a standing start onto plane.Bow UpToo much trim-out puts the bow of the boattoo high in the water. Performance and econ-omy are decreased because the hull of theboat is pushing the water and there is more airdrag. Excessive trim-out can also cause thepropeller to ventilate, which reduces perfor-mance further, and the boat may “porpoise”(hop in the water), which could throw the op-erator and passengers overboard.Bow DownToo much trim-in causes the boat to “plow”through the water, decreasing fuel economyand making it hard to increase speed. Operat-ing with excessive trim-in at higher speedsalso makes the boat unstable. Resistance atthe bow is greatly increased, heightening thedanger of “bow steering” and making opera-tion difficult and dangerous.NOTE:Depending on the type of boat, the outboardmotor trim angle may have little effect on thetrim of the boat when operating.EMU27934Tilting up and downIf the engine will be stopped for some time orif the boat is moored in shallows, the outboardmotor should be tilted up to protect the propel-ler and lower casing from damage by collisionwith obstructions, and also to reduce salt cor-rosion.WARNINGEWM00221Be sure all people are clear of the out-board motor when tilting up and down,Body parts can be crushed between themotor and the clamp bracket when the mo-tor is trimmed or tilted.WARNINGEWM00250Leaking fuel is a fire hazard. If there is afuel joint on the outboard motor, discon-nect the fuel line or close the fuel cock ifthe engine will be tilted for more than a fewminutes. Otherwise fuel may leak.