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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 SetupInstalled 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.
🏁 FitmentCompatible 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.
📏 SpecificationsBore 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.
Bayside Powersports LLCWe specialize in performance carburetors and 2-stroke components. Fast shipping and knowledgeable support for serious YZ builds.