Honda G100K2 Applications Manual page 12

JETTING
At high altitudes, the air is less dense and the standard carburetor main jet will produce an excessively rich air-fuel
mixture. Performance will decrease and fuel consumption will increase as a result.
High altitude performance can be improved by installing a smaller diameter main jet. With suitable carburetor
jetting, engine horsepower will decrease approximately 10% for each 1000-meter increase in altitude. The effect
of altitude on horsepower will be greater than this if a high altitude main jet is not installed.
The following chart shows the effect of altitude on horsepower when the carburetor is correctly jetted.
Before ordering or calculating optional jets, always check the mounted standard jet.
For some types, variations or countries this may differ.
Main jet: number
of reduction
Example: At an altitude of 1500 meters, use a jet size correction factor of 85%. If the standard main jet is # 68,
The recommended jet for an altitude of 2000 meters would be # 65 (68-3 = 65).
For quick reference, the size of a jet can be easily found through the part number.
For example: 99101-ZF5-0850
99101-ZF5-0800
99101-ZF5-0820
Note:
At an altitude of 1500 meters, a correctly jetted engine is capable of delivering approximately 85% of its sea
level maximum power.
For continuous loads, the engine should not be required to deliver more than 85% of its sea level maximum
power.
Altitude
jet # 85
jet # 80
jet # 82
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FUEL SYSTEM
Atmospheric pressure