HONDA Outboard Motor BF90A - Manual (Page 114)

12V 70AH
112
Carburetor Modification for
High Altitude Operation Battery
Minimum Requirements
TECHNICAL AND CONSUMER INFORMATION
When the carburetors have been
modif ied f or high altitude operation,
the air-f uel mixture will be too lean
f or low altitude use. Operation at
altitudes below 5,000 f eet (1,500
meters) with modif ied carburetors
may cause the engine to overheat
and result in serious engine damage.
For use at low altitudes, have an
authorized Honda Marine dealer
return the carburetors to original
f actory specif ications.
At high altitude, the standard
carburetor air-fuel mixture will be
too rich. Performance will decrease,
and fuel consumption will increase.
A very rich mixture will also foul the
spark plugs and cause hard starting.
High altitude performance can be
improved by specific modifications
to the carburetors. If you always
operate your outboard motor at
altitudes above 5,000 feet (1,500
meters), have an authorized Honda
marine dealer perform this carburetor
modification.
Even with carburetor modification,
engine horsepower will decrease
about 3.5% for each 1,000-foot (300-
meter) increase in altitude. The effect
of altitude on horsepower will be
greater than this if no carburetor
modification is made.
For complete information, refer to
the battery manufacturer’s
instructions.
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