Operation At High Altitude - Firman ECO4000 Owner's Manual

Operation at High Altitude

The density of air at high altitude is lower than at sea level. Engine power is
reduced as the air mass and air-fuel ratio decrease. Engine power and generator
output will be reduced approximately 3% for every 1000 feet of elevation above sea
level. This is a natural trend and cannot be changed by adjusting the engine. At
high altitudes increased exhaust emissions can also result due to the increased
enrichment of the air fuel ratio.
Other high altitude issues can include hard starting, increased fuel consumption
and spark plug fouling. To alleviate high altitude issues other than the natural
power loss, FIRMAN can provide a high altitude carburetor main jet.The alternative
main jet and installation instructions can be obtained by contacting Customer
Support. Installation instructions are also available in the Technical Bulletin area of
the FIRMAN internet site.
The part number and recommended minimum altitude for the application of the
high altitude carburetor main jet is listed in the table below.
In order to select the correct high altitude main jet it is necessary to identify the
carburetor model. For this purpose, a code is stamped on the side of the
carburetor. Select the correct main jet part number corresponding to the carburetor
code found on your particular carburetor.
Standard main jet
Altitude main jet 1
Altitude main jet 2
WARNING
Operation using the alternative main jet at elevations lower than the recommended
minimum altitude can damage the engine. For operation at lower elevations, the
standard main jet must be used. Operating the engine with the wrong engine
configuration at a given altitude may increase its emissions and decrease fuel
efficiency and performance.
196cc 389cc
468.131017.07 188.131017.04
468.131017.08
188.131017.05
188.131017.06
468.131017.09
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193cc Altitude
0-3000Feet
468.131017.03
490.131017.04 3000-6000Feet
490.131017.05 6000-8000Feet
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