DUROMAX XP9HP - High Altitude Operation

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High Altitude Operation
ENGINE SETUP (CONTINUED)
At high altitudes, the standard carburetor air/fuel mixture will be too rich. The 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 diers from that at which this engine was certied, for extended periods of
time, may increase emissions. High altitude performance can be improved by specic modications to
the carburetor. If you always operate your engine at altitudes above 3,000 feet (900 meters), have a dealer
perform this carburetor modication. This engine, when operated at high altitude with the carburetor
modications for high altitude use, will meet each emission standard throughout its useful life. Even with
carburetor modication, engine horsepower will decrease by about 3.5% for each 1,000-foot (300-meter)
increase in altitude. The eect of altitude on horsepower will be greater than this if no carburetor
modication is made.
When the carburetor has been modied for high altitude operation, the air/fuel mixture will be too lean for
low altitude use. Operation at altitudes below 3,000 feet (900 meters) with a modied carburetor may cause
the engine to overheat and result in serious engine damage.
Note: Jet kits available for purchase upon request, please contact us at 844-DUROMAX to set up your
parts order.