High Altitude Operation - Honda WT20X Owner's Manual

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 installing a smaller diameter
main fuel jet in the carburetor and readjusting the pilot screw. If you always
operate.the pump at altitudes higher than 6,000 feet above sea level, have
y'our authorized Honda pump dealer perform these carburetor
modifications.
Even with suitable carburetor jetting, engine horsepower will decrease ap-
proximately 3.5% for each 1,000 foot increase in altitude. The effect of
altitude on horsepower will be greater than this if no carburetor modifica-
tion 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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