John Deere PR-G7500M - Manual (Page 15)

PREPARING THE GENERATOR
Operator’s Manual 15
GENERAL RECOMMENDATIONS
• Purchase gasoline in small quantities and store in clean,
approved containers.
• To minimize gum deposits in your fuel system and to
insure easy starting, do not use gasoline left over from
the previous season.
• Do not add oil to the gasoline.
FUEL TYPE
• For best results use only clean, fresh, unleaded gasoline
with a pump sticker octane rating of 87 or higher.
• Unleaded gasoline is recommended as it leaves less
combustion chamber deposits.
GASOLINE/ALCOHOL BLENDS:
Gasohol (up to 10% ethyl alcohol, 90% unleaded gasoline
by volume) is approved, as a fuel. Other gasoline/alcohol
blends are not approved.
GASOLINE/ETHER BLENDS:
Methyl Tertiary Butyl Ether (MTBE) and unleaded gasoline
blends (up to a maximum of 15% MTBE by volume) are
approved as a fuel. Other gasoline/ether blends are not ap-
proved.
HIGH ALTITUDE
At high altitude, the standard carburetor air/fuel mixture will
be too rich. Performance will decrease, and fuel consump-
tion 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 ex-
tended periods of time, may increase emissions.
High altitude performance can be improved by specific
modifications to the carburetor. If you always operate your
generator at altitudes above 5,000 feet (1,500 meters),
have your 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.
NOTE:When the carburetor has been modified for high altitude opera-
tion, 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.