YD-MJN30 Racing Carburetor 30mm for MSX125 Big Bore Pit Bike & ATV

Product Overview

Build for stronger top-end performance with this YD-MJN30 Racing Carburetor, designed for Honda MSX125 / Grom-style performance builds, pit bikes, dirt bikes, ATVs, and go-karts using modified or big bore engine setups.

With a larger 30mm inner diameter, this carburetor is better suited for engines that need increased airflow at higher RPM. It is a strong option for racing builds where top-end power, high-speed performance, and aggressive acceleration are more important than low-speed stock-style drivability.

The MJN-style fuel needle system helps improve fuel atomization, while the dual stack velocity intake supports smoother airflow into the engine. Because this is a performance carburetor, proper tuning, jetting, and setup are required for best results.

Product Compatibility

Category	Fitment
Primary Model	Honda MSX125 / Grom-style engines
Engine Type	Modified 125cc / big bore performance engines
Vehicle Type	Pit Bike, Dirt Bike, ATV, Go-Kart
Build Type	Racing, Big Bore, High-Output Performance Upgrade
Carburetor Size	30mm inner diameter

Specifications

Specification	Details
Model	YD-MJN30
Carburetor Type	Racing Performance Carburetor
Inner Diameter	30mm / 1.18"
Technology	MJN-style Multiple Jet Needle
Intake Design	Dual Stack Velocity Intake
Material	High-strength alloy
Recommended Use	Top-end power / big bore racing builds
Condition	100% New

Key Features

• 30mm High-Flow Design – Provides increased airflow for high-RPM and big bore engine performance.
• Built for Top-End Power – A strong choice for racing builds that need more upper-range output.
• MJN-Style Fuel Technology – Helps create finer fuel atomization for smoother and more efficient combustion.
• Dual Stack Velocity Intake – Improves intake airflow stability and supports stronger acceleration.
• Performance Upgrade for Tuned Engines – Suitable for modified MSX125-style engines, pit bikes, ATVs, and go-karts.

Need Faster Throttle Response?

If you want sharper throttle response and stronger mid-range acceleration for a 125cc performance build, the YD-MJN28 28mm Racing Carburetor may be a better choice. The 28mm version is easier to match with smaller modified engines.