Notes Regarding Air Filter Boots (Air Boots) on Certain Models:
Some OEM or replica air boots have overly complicated internal shapes, including excessive ridges, steps, chambers, sharp transitions, and irregular surfaces inside the intake tract. At mid to high RPM, these structures can create severe airflow turbulence.
This unstable airflow can directly interfere with the carburetor’s internal pressure balance and venting system, leading to symptoms such as poor high-RPM revving, dull power delivery, lean conditions at high RPM, hanging idle, or inconsistent fueling behavior.
It is recommended to carefully smooth and reshape the inside of the air boot by removing unnecessary protrusions, sharp edges, and irregular internal structures, allowing the airflow path to remain as smooth, straight, and continuous as possible.
The goal is not to enlarge the intake passage, but to reduce turbulence and stabilize airflow. On some Chinese-manufactured models, replacing the air boot with an OEM KTM air boot has completely eliminated these high-RPM fueling issues.
The above content will be included in the next version of our user manual.
