GEN3+ For Beta 300 RX
Beta 300RX (2021–2025)
Torque Gain Circuit Recommendation
The Torque Gain Circuit is an additional fuel enrichment system designed to activate at lower throttle openings than the standard Power Jet circuit.
It can be understood as a secondary fuel assist circuit, or a low-throttle activation version of the Power Jet system. Unlike a traditional Power Jet that typically becomes effective near 1/2 throttle and above, the Torque Gain Circuit begins supplying additional fuel at earlier throttle positions and under higher engine load conditions.
This concept is very similar to the auxiliary enrichment design used on the Lectron Billetron Pro series.
We especially recommend this option for:
* Riders using high-ethanol fuel blends (such as in Brazil)
* Extreme riding environments with long-distance, sustained full-throttle operation
* Riders who want earlier and faster activation of the Power Jet effect under load
For standard riding conditions and conventional non-ethanol fuel, this circuit is generally not necessary.
Richer-Calibrated Metering Rod Recommendation
For riders who have already upgraded, or plan to upgrade, their engines with high-compression cylinder heads, modified cylinders, aggressive porting, racing exhaust systems, or other advanced engine modifications—and who want a wider tuning range—we strongly recommend purchasing an additional richer-calibrated metering rod as a backup option.
Throttle Assembly Recommendation
For the best riding experience, we highly recommend using our recommended throttle assembly together with the carburetor. It provides a smoother and more precise throttle feel, improved control accuracy, and a more refined riding experience across all riding conditions.
We provide one free throttle cable for every customer after placing an order.
If you do not plan to purchase our recommended throttle assembly, please select the correct throttle cable when placing your order so it can work properly with your original throttle assembly.
M8 throttle cable mainly covers:
Yamaha, Kawasaki, and Suzuki 125cc+ two-stroke models, such as YZ125/YZ250, KX125/KX250, RM125/RM250, etc.
M10 throttle cable mainly covers:
European models such as KTM, Husqvarna, GasGas, Beta, Sherco, and TM, especially models using Domino throttle assemblies. Honda two-stroke OEM throttle assemblies also belong to the 10mm series.
M10-90° / 4-stroke long cable mainly covers:
DRZ400, XR650R/L, KTM four-stroke models, etc.
If you choose our recommended throttle assembly, please note that this throttle assembly is only compatible with M10 throttle cables. In that case, please choose the correct M10 cable type: either the straight-end throttle cable or the 90-degree angled throttle cable.
Each XTNG carburetor is carefully pre-set at the factory based on the detailed information you provide. By taking into account your engine configuration, exhaust setup, riding style, fuel type, and premix ratio, we are able to deliver a highly refined baseline setting tailored specifically to your bike. This ensures an optimal air-fuel ratio across the entire operating range, improving efficiency, consistency, and overall rideability right out of the box.
Please note: XTNG carburetors are currently designed and calibrated primarily for use with standard gasoline fuels. At this time, ethanol-heavy fuels, alcohol fuels, and methanol-based racing fuels are not officially supported.





