Honda Harmony HRB215SDA Owner's Manual page 52

MAINTENANCE
Carburetor Adjustment
1. Start the engine outdoors, and
allow it to warm up to normal
operating temperature.
2. Set the throttle lever in the
SLOW position.
3. Turn the throttle stop screw to
obtain the standard idle speed.
Standard idle speed:
2,100 ~150 rpm
THROTTLE STOP SCREW
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.
High altitude performance can be improved by specific modifications
to the carburetor. If you always operate your mower at altitudes
above 5,000 feet (1,500 meters) have an authorized Honda servicing
dealer perform this carburetor modification.
Even with carburetor modification, engine horsepower will decrease
about 3.5% for each 1 ,OOO-foot (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 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 an authorized Honda
servicing dealer return the carburetor to original factory specifications.
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