High Altitude Carburetor Adjustment - Honda TRX400FA 2005 Owner's Manual

High Altitude Carburetor Adjustment

Your engine's air-fuel mixture becomes overly rich when operated at
high altitudes. Above 3,000 feet (1,000 m), a rich mixture can cause
driveability problems, reduce engine performance, and increase fuel
consumption. To compensate, you can have the carburetor adjusted for
high altitude riding. See your Honda dealer.
A high altitude jet is available to compensate for high altitude richness.
For those who are mechanically proficient and have the necessary tools,
installation and adjustment procedures are given in the official Honda
Service Manual available from your Honda dealer. All others should
have this carburetor modification performed by a Honda dealer.
However, the carburetor must be returned to standard factory
specifications before riding again at lower altitudes (below 4,500 feet,
1,500 m).
Sustained riding at lower altitudes with the lean high-altitude setting
may cause rough idling, stalling, or engine damage from overheating.
Technical Information
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