Cruising In Shallows; High Altitude Operation - Honda BF4A Operation And Maintenance Ma

OPERATION

Cruising in Shallows

When cruising in shallows, tilt up the
outboard motor to prevent the
propeller and gear case from hitting
bottom.
Refer to "Tilting the Outboard
Motor" (page 57) for the procedure.
• Be sure that the water is coming
out of the cooling water check
hole.
• When the outboard motor is
tilted up, cruise at low speed.
60

High Altitude Operation

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 plug and cause hard starting.
High altitude performance can be
improved by specific modifications to
the carburetor. If you always operate
the outboard motor at altitudes higher
than 1,500 m (5,000 feet) above sea
level, have your authorized Honda
dealer perform these carburetor
modifications.
Even with suitable carburetor jetting,
engine horsepower will decrease
approximately 3.5% for each 300 m
(1,000 feet) increase in altitude. The
effect of altitude on horsepower will
be greater than this if no carburetor
modification is made.
When the carburetor have been
modified for high altitude
operation, the air-fuel mixture will
be too lean for low altitude use.
Operation at altitudes below 1,500
m (5,000 feet) with modified
carburetor may cause the engine to
overheat and result in serious
engine damage. For use at low
altitudes, have an authorized
Honda outboard motor dealer
return the carburetor to original
factory specifications.