Mikuni TMX 38mm Carburetor Yamaha YZ125 1999-2004 Tuned

Upgrade your Yamaha YZ125 (1999–2004) with a Mikuni TMX 38mm flatslide carburetor, professionally tuned to provide strong throttle response and smooth power delivery.

This carburetor is set up with a proven baseline jetting to suit most stock and lightly modified YZ125 engines.

Ideal for motocross, woods riding, and race builds.

Installed jetting:

• 410 Main Jet

• 40 Pilot Jet

This setup provides a strong starting point for most 1999–2004 YZ125 applications.

⚠ Final tuning may be required depending on:

• Elevation

• Temperature

• Exhaust system

• Reed cage setup

• Engine modifications

• 38mm high-flow bore

• TMX flatslide design for instant throttle response

• Strong mid-range acceleration

• Improved top-end power

• Excellent fuel atomization

• Fully tunable jetting system

The flatslide design delivers a sharper, more responsive throttle feel compared to worn stock carburetors.

Compatible with:

• Yamaha YZ125 (1999–2004)

Earlier models in this range may require the intake boot and/or airbox boot to be softened or heated to properly fit and seal this 38mm carburetor.

This is common when upgrading to a larger performance carburetor and helps ensure a secure, airtight connection.

Please confirm intake diameter and throttle cable compatibility before purchase.

• Bore Size: 38mm

• Type: Mikuni TMX Flatslide

• Mount: Spigot mount

• Manual choke

• Adjustable needle position

• Mikuni TMX 38mm Carburetor

• 410 Main Jet (installed)

• 40 Pilot Jet (installed)

Professional installation and proper jet tuning are recommended for optimal performance and engine safety.

We specialize in performance carburetors and 2-stroke components. Fast shipping and knowledgeable support for serious YZ builds.