Carburetor Modification For High Altitude Operation - Honda F300 Owner's Manual

4MV488000.book 55 ページ ２０１６年３月２日 水曜日 午後１２時３６分
TECHNICAL INFORMATION

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 your tiller at altitudes above
1,500 meters, have your 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 300-meter increase in altitude. The effect of
altitude on horsepower will be greater than this if no carburetor
modification is made.
When the carburetor has been modified for high altitude operation, the
air-fuel mixture will be too lean for low altitude use. Operation at
altitudes below 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 your servicing dealer return the carburetor to original
factory specification.
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