Mikuni TMX 38mm Carburetor – Yamaha YZ125 (1999–2004) – Tuned Setup
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.
🔥 Tuned Setup
Installed jetting:
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
🔥 Performance Benefits
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.
🏁 Fitment
Compatible with:
🔧 Fitment Note for Earlier Years (1999–2001)
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.
📏 Specifications
Bore Size: 38mm
Type: Mikuni TMX Flatslide
Mount: Spigot mount
Manual choke
Adjustable needle position
Engine Side (Spigot OD): 46mm
Air Filter Side (OD): 62mm
Overall Length: Approximately 164mm
Overall Width: Approximately 76mm
Float Height: 20mm
Flat Slide Design
Cable Operated Choke
📦 Package Includes
⚠ Installation Notice
Professional installation and proper jet tuning are recommended for optimal performance and engine safety.
Bayside Powersports LLC
We specialize in performance carburetors and 2-stroke components. Fast shipping and knowledgeable support for serious YZ builds.
Important Fitment Notice
Please read the entire listing before purchasing. Detailed fitment information, specifications, measurements, compatible years/models, and installation notes are provided in the description.
It is the buyer's responsibility to verify that this part is correct for their specific machine. Please compare your existing part and measurements before ordering. Do not rely solely on the compatibility chart, as it is only a general guide.
If you are unsure about fitment, contact us before purchasing?we're happy to help.
Orders placed without verifying compatibility that result in the wrong item being purchased are considered buyer error.
Orders placed without verifying compatibility that result in the incorrect item being purchased are considered buyer error. Returns for buyer error may be subject to a 25% open-box deduction.
Items returned in used, installed, damaged, or otherwise diminished condition may be subject to up to a 50% deduction from the refund, consistent with our return policy and applicable seller protections.
