TECHNICAL AND CONSUMER INFORMATION
60
Carburetor Modification for 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.
Operation at an altitude that differs from that at which this engine was
certified, for extended periods of time, may increase emissions.
High altitude performance can be improved by specific modifications to
the carburetor. If you always operate the pump above 5,000 feet
(1,500 meters), have an authorized Honda servicing dealer perform
this carburetor modification. This engine, when operated at high
altitude with the carburetor modifications for high altitude use, will meet
each emission standard throughout its useful life.
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.
NOTICE
When the carburetor is modified for high altitude operation, the air fuel
mixture will be too lean for low altitude use. Operation at altitudes
below 5,000 feet (1,500 meters) with a modified carburetor may cause
the engine to overheat and result in serious engine damage. For use at
low altitudes, have an authorized Honda servicing dealer return the
carburetor to original factory specifications.
