Carburetor adjustment for tuning air filter box lid

To increase the performance of the Kmx, you can install the tuning air filter box cover. The opening of the cover is about 60% larger than that of the original cover. This allows the carburetor to draw in more air, thus generating a little more power.

What do I need to consider?

More air with the same amount of gasoline creates a lean mixture and therefore more heat. Therefore, the spark plug reading must be checked after installation! The spark plug should be reddish-brown; if it is darker to black, it is running too rich. To correct this, simply install a smaller main jet. If it is lighter to white, the Kmx is running too lean! This can lead to engine damage in the long run. To prevent this, you can install a larger main jet. Originally, a 102.5 main jet is installed. With the air filter box cover, it is better to use a 107.5 - 112.5 main jet. It is better to start with a main jet that is too large rather than too small.

How do I check the spark plug reading correctly?

How you check the spark plug reading is particularly important! To find the correct main jet, sit on your Kmx and ride at full throttle for about one kilometer with a well-warmed-up engine. Then immediately switch off the engine (kill switch or ignition) and stop at the next opportunity. Then unscrew the spark plug and check the spark plug reading.

Light spark plug = Lean mixture (More air than gasoline)

Dark spark plug = Rich mixture (More gasoline than air)

Reddish-brown spark plug = Optimal mixture (Gasoline-air mixture is perfect)

Caution!

Two-strokes tend to lean out during longer full-throttle rides, which is why we recommend installing a large main jet first and then working your way down.

Have a good trip!