An outboard motor is a
propulsion system for
boats, consisting
of a self-contained unit that includes engine, gearbox and
propeller or
jet drive,
designed to be affixed to the outside of the
transom. They are the most common motorized
method of propelling small watercraft. As well as providing propulsion,
outboards provide steering control, as they are designed to pivot over their
mountings and thus control the direction of thrust. The
skeg also acts as a
rudder when the
engine is not running. Compared to
inboard motors, outboard motors can be easily removed for storage or
repairs.
In order to eliminate the chances of hitting bottom with an
outboard motorr, the motor can be tilted up to
an elevated position either electronically or manually. This helps when
traveling through shallow waters where there may be debris that could
potentially damage the motor as well as the propeller.
If the electronic motor required to move the pistons which raise or lower the
engine is malfunctioning, every outboard motor is equipped with a manual piston
release which will allow the operator to drop the motor down to its lowest
setting.
The creation of the first practical and marketable outboard motor is often
miscredited to Norwegian-American inventor
Ole
Evinrude in 1909. Between 1909 and 1912, Evinrude made thousands of his
outboards and the three horse units were sold around the world. His Evinrude
Outboard Co. was spun off to other owners, and he went onto success with
ELTO. The 1920s
were the first highwater mark for the outboard with Evinrude, Johnson, ELTO,
Atwater Lockwood and dozens of other makers in the field.
Historically, a majority of outboards have been two-stroke
powerheads fitted with a carburetor due to the design's inherent simplicity,
reliability, low cost and light weight. Drawbacks include increased pollution,
due to the high volume of unburned gasoline in their exhaust, and louder noise.
In the 1990s, US and European exhaust emissions regulations led to the
proliferation of four-stroke outboards.
Read the full history of Outboard Motors at Wikipedia
by clicking here.