High Altitude Operation; Oxygenated Fuels; Emission Control System Information - Honda GXV160 Owner's Manual

6. Start the engine and move the throttle lever to the fast (or high)
position. Using a tachometer, check the engine speed. Turn screw
A to obtain the top no load engine speed specified by the
equipment manufacturer.
7. N types: Move the throttle cable control lever to the stop position
and confirm that the engine shuts off.
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.
Operation at an altitude that differs from that at which this engine was
certified, for extended periods of time, may increase emissions.
High altitude performance can be improved by specific modifications to
the carburetor. If you always operate your engine at altitudes above
5,000 feet (1,500 meters), have your servicing dealer perform this
carburetor modification. This engine, when operated at high altitude
with the carburetor modifications for high altitude use, will meet each
emission standard throughout its useful life.
Even with carburetor modification, engine horsepower will decrease
about 3.5% for each 1,000-foot (300-meter) increase in altitude. The
effect of altitude on horsepower will be greater than this if no
carburetor modification is made.
NOTICE
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 dealer return the
carburetor to original factory specifications.
10

Oxygenated Fuels

Some conventional gasolines are being blended with alcohol or an
ether compound. These gasolines are collectively referred to as
oxygenated fuels. To meet clean air standards, some areas of the
United States and Canada use oxygenated fuels to help reduce
emissions.
CHOKE ARM
If you use oxygenated fuel, be sure it is unleaded and meets the
minimum octane rating requirements.
Before using an oxygenated fuel, try to confirm the fuel's contents.
Some states/provinces require this information to be posted on the
pump.
The following are the EPA approved percentages of oxygenates:
ETHANOL —
MTBE —
METHANOL —
If you notice any undesirable operating symptoms, try another service
station or switch to another brand of gasoline.
Fuel system damage or performance problems resulting from the use
of an oxygenated fuel containing more than the percentages of
oxygenates mentioned above are not covered under the Distributor's
Limited Warranty.

Emission Control System Information

Source of Emissions
The combustion process produces carbon monoxide, oxides of
nitrogen, and hydrocarbons. Control of hydrocarbons and oxides of
nitrogen is very important because, under certain conditions, they
react to form photochemical smog when subjected to sunlight. Carbon
monoxide does not react in the same way, but it is toxic.
Honda utilizes lean carburetor settings and other systems to reduce
the emissions of carbon monoxide, oxides of nitrogen, and
hydrocarbons.
The U.S., California Clean Air Acts and Environment Canada
EPA, California and Canadian regulations require all manufacturers to
furnish written instructions describing the operation and maintenance
of emission control systems.
The following instructions and procedures must be followed in order to
keep the emissions from your Honda engine within the emission
standards.
English
(ethyl or grain alcohol) 10% by volume
You may use gasoline containing up to 10%
ethanol by volume. Gasoline containing ethanol
may be marketed under the name Gasohol.
(methyl tertiary butyl ether) 15% by volume
You may use gasoline containing up to 15%
MTBE
by volume.
(methyl or wood alcohol) 5% by volume
You may use gasoline containing up to 5%
methanol by volume as long as it also contains
cosolvents and corrosion inhibitors to protect the
fuel system. Gasoline containing more than 5%
methanol by volume may cause starting and/or
performance problems. It may also damage
metal, rubber, and plastic parts of your fuel
system.