MAINTENANCE & ADJUSTMENTS
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 installing a smaller
diameter main fuel jet in the carburetor and readjusting the pilot
screw. If you always operate the mower at altitudes higher than
1,800 meters (6,000 feet) above sea level, have an authorized
Honda lawn mower dealer perform this carburetor modification.
Even with carburetor modification, engine horsepower will
decrease about 3.5% for each 300 meter(1 ,000 foot ) increase in
altitude. The effect of altitude on horsepower will be greater than
this if no carburetor modification is made. A reduction in engine
horsepower will reduce mowing performance.
l-izG-l
When the carburetor is modified for high altitude operation, the
air-fuel mixture will be too lean for low altitude use. Operation at
altitudes below 1,800 meters (6,000 feet), with high altitude
carburetor modifications, may cause the engine to overheat and
result in serious engine damage. For low altitude use, reinstall
the standard main fuel jet, and readjust the pilot screw.