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TECHNICAL & CONSUMER INFORMATION
Carburetor Modificationfor High Altitude Operation
At high altitude, the standard carburetor air-fuel mixturewill be too
rich. Performancewill decrease, and fuel consumption will increase. A
very rich mixturewill also f oulthe 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, mayincrease emissions.
High altitude performance can be improved by specific modifications
to the carburetor. If you always operate your pump ataltitudes above
5,000 feet (1,500 meters) have yourservicing dealer perform this
carburetor modification.This e ngine,when operated at high altitude
with the caruburetor modifications for high altitude use, will meet
each emission standard throughoutits usef ul life.
Even with carburetor modification,engine horsepower will decrease
about 3.5 % for each 1,000-foot (300-meter) increasein 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 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 your servicing dealerreturn the
carburetor to original factory specifications.
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