Mariner 100, Service Manual, Page: 15 / 391

1-10 90-13645--2 495 GENERAL INFORMATION AND SPECIFICATIONS
Out-of-Season Battery Storage
1. Remove battery as soon as possible and remove
all grease, sulfate and dirt from top surface.
2. Cover PLATES with distilled water, but not over
3/16 in. (5mm) above perforated baffles.
3. Cover terminal bolts well with grease.
4. Store battery in a COOL, DRY place in a dry car-
ton or box.
5. Remove battery from storage every 60 days.
Check water level and place on charge for 5 to 6
hours at 6 amperes. DO NOT fast charge.
A discharged battery can be damaged by freezing.
CAUTION
How Weather Affects Engine
Performance
It is a known fact that weather conditions exert a pro-
found effect on power output of internal combustion
engines. Therefore, established horsepower ratings
refer to the power that the engine will produce at its
rated RPM under a specific combination of weather
conditions.
Corporations internationally have settled on adoption
of I.S.O. (International Standards Organization)
engine test standards, as set forth in I.S.O. 3046
standardizing the computation of horsepower from
data obtained on the dynamometer, correcting all
values to the power that the engine will produce at
sea level, at 30% relative humidity at 77
F (25 C)
temperature and a barometric pressure of 29.61
inches of mercury.
Summer Conditions of high temperature, low baro-
metric pressure and high humidity all combine to re-
duce the engine power. This, in turn, is reflected in de-
creased boat speeds--as much as 2 or 3 miles-per-
hour (3 or 5 Km per-hour) in some cases. (Refer to
previous chart.) Nothing will regain this speed for the
boater, but the coming of cool, dry weather.
In pointing out the practical consequences of weather
effects, an engine--running on a hot, humid summer
day--may encounter a loss of as much as 14% of the
horsepower it would produce on a dry, brisk spring or
fall day. The horsepower, that any internal combus-
tion engine produces, depends upon the density of
the air that it consumes and, in turn, this density is de-
pendent upon the temperature of the air, its baromet-
ric pressure and water vapor (or humidity) content.
Accompanying this weather-inspired loss of power is
a second but more subtle loss. At rigging time in early
spring, the engine was equipped with a propeller that
allowed the engine to turn within its recommended
RPM range at full throttle. With the coming of the sum-
mer weather and the consequent drop in available
horsepower, this propeller will, in effect, become too
large. Consequently, the engine operates at less than
its recommended RPM.
Due to the horsepower/RPM characteristics of an en-
gine, this will result in further loss of horsepower at the
propeller with another decrease in boat speed. This
secondary loss, however, can be regained by switch-
ing to a smaller pitch propeller that allows the engine
to again run at recommended RPM.