OPERATiON
23
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 water pump output will be reduced
approximately 3½% for every 1000 ft. 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, Black Diamond can provide a high altitude carburetor main
jet. The alternative main jet and installation instructions can be
obtained by contacting our Technical Support Team.
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 high
altitude jet part number corresponding to the carburetor code
found on your particular carburetor.
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 originally
supplied 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.
