Yamaha 25B Manual Del Propietário página 108

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EMU00282
Bow Up
When the boat is on plane, a bow-up attitude
result in less drag, greater stability and effi-
ciency. This is generally when the keel line of
the boat is up about 3 to 5 degrees. When
trimmed out, the boat may have more ten-
dency to steer to one side or the other. Com-
pensate for this as you steer. The trim tab
can also be adjusted to help offset this effect.
Too much trim-out puts the bow of the boat
too high in the water. Performance and econ-
omy are decreased because the hull of the
boat is pushing the water and there is more
air drag.
Excessive trim-up can cause the propeller to
ventilate, which reduces performance further.
When trimmed-out too much, a boat may
"porpoise" (hop in the water), which could
105011
throw the operator and passengers over-
board.
EMU00283
Bow Down
When the bow of the boat is down, it is easi-
er to accelerate from a standing start onto
plane.
Too much trim-in causes the boat to "plow"
through the water, decreasing fuel economy
105013
and making in hard to increase speed.
Operating with excessive trim-in at higher
speeds also makes the boat unstable. Resis-
tance at the bow is greatly increased, height-
ening the danger of "bow steering" and mak-
ing operation difficult and dangerous.
1 Bow up
2 Bow down
3 Optimum angle
105015
3-25
GB