High Altitude Operation - Honda WB20XT Guide De L'utilisateur

6. If the choke lever was moved to the CLOSED position to start the engine,
gradually move it to the OPEN position as the engine warms up.
CHOKE LEVER
OPEN
OPEN

• High altitude operation

At high altitude, the standard carburetor air-fuel mixture will be excessively rich.
Performance will decrease, and fuel consumption will increase.
High altitude performance can be improved by specific modifications to the
carburetor. If you always operate the pump at altitudes higher than 610 m
(2,000 feet) above sea level, have your servicing dealer perform these carburetor
modifications.
Even with suitable carburetor jetting, engine horsepower will decrease
approximately 3.5 % for each 300 m (1,000 foot) increase in altitude. The effect
of altitude on horsepower will be greater than this if no carburetor modification
is made.
CAUTION:
Operation of the pump at an altitude lower than the carburetor is jetted for
may result in reduced performance, overheating, and serious engine
damage caused by an excessively lean air/fuel mixture.
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