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38mm Mikuni TMX Flat Slide Carburetor - Custom Tuned
Upgrade your machine with this high-quality aftermarket 38mm Mikuni TMX flat slide carburetor. Featuring a smooth-bore venturi and flat-slide design, it delivers crisp throttle response, improved fuel atomization, excellent low-end torque, strong mid-range power, and outstanding top-end performance.
Every carburetor is personally custom tuned by me before shipment using a proven baseline jetting setup. This provides an excellent starting point for most applications while still allowing for final jetting adjustments based on engine modifications, altitude, fuel type, and riding aftermarket replacement carburetor
Personally custom tuned before shipment
38mm Mikuni TMX flat-slide design
High-flow smooth-bore venturi
Crisp throttle response
Excellent low-end torque
Strong mid-range and top-end performance
Includes spare main and pilot jets for fine tuning
Durable aluminum 38mm
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 (2000-2001) - Performance upgrade from the original 36mm Mikuni TMX carburetor.
CR125R (2002-2007) - Direct replacement for the OEM 38mm Mikuni TMX carburetor.
CR250R (2001-2003) - Direct replacement for the OEM 38mm Mikuni TMX carburetor.
Honda CR125R Notes
2001 models use the non-TPS 38mm Mikuni TMX carburetor.
2002-2007 models use a 38mm Mikuni TMX equipped with a Throttle Position Sensor (TPS).
This replacement carburetor does not utilize a TPS. Simply leave the factory TPS connector unplugged during (2001-2021) - Direct replacement for the OEM 38mm Mikuni TMX carburetor.
Yamaha YZ125 Notes
2001 was the transition year from the 36mm TMX to the 38mm TMX.
OEM carburetors are commonly identified as the Mikuni TMX38SS.
Later model years may have minor casting or jetting revisions but remain 38mm TMX (1998-2002) - Performance upgrade from the original 36mm Mikuni TMX carburetor.
KX125 (2003-2005) - Direct replacement for the OEM 38mm Mikuni TMX carburetor.
KX250 (2001-2004) - Direct replacement for the OEM 38mm Mikuni TMX carburetor.
Kawasaki Notes
1998-2002 KX125 models originally used a 36mm TMX and can benefit from the increased airflow of the 38mm TMX when properly tuned.
2003-2005 KX125 and 2001-2004 KX250 models were factory equipped with a 38mm Mikuni TMX (1996-2000) - Performance upgrade from the original 36mm Mikuni TMX carburetor.
RM125 (2001-2006) - Direct replacement for the OEM 38mm Mikuni TMX SX (2017-2019)
150 SX (2017-2019)
250 SX (2017-2019)
300 XC (2017-2019)
300 XC-W (2008-2012) - Direct replacement for the OEM 38mm Mikuni TMX carburetor.
Installation Notes
Some applications may require heating and softening the original intake boot and/or airbox boot during installation. Over time, factory rubber boots become hard from age and heat exposure, making installation more difficult.
Carefully warming the boots with a heat gun or hot water will usually restore enough flexibility for proper installation.
Depending on your application, an aftermarket throttle cable, intake boot, reed spacer, or other minor modifications may also be required.
Please compare your original carburetor dimensions before purchasing.
Every carburetor is personally custom tuned before shipment using a proven baseline setup. Final jetting may still be required depending on your engine modifications, exhaust system, reed valves, airbox configuration, altitude, fuel type, and weather conditions.
Package Includes
This aftermarket 38mm Mikuni TMX flat-slide carburetor is an excellent replacement or performance upgrade for a wide variety of 125cc-300cc two-stroke motorcycles. Every carburetor is personally inspected and custom tuned before shipping to provide a reliable baseline setup, helping you spend less time tuning and more time riding.
Important Fitment Notice
Please read the entire listing before purchasing. Detailed fitment information, specifications, dimensions, compatible years/models, and installation notes are provided throughout this listing.
It is the buyer's responsibility to verify compatibility before purchasing.
Please compare your existing carburetor and dimensions before ordering.
Do not rely solely on the compatibility chart, as it is only a general guide.
If you are unsure about fitment, please contact us before purchasing—we're happy to help.
Orders placed without verifying compatibility that result in the incorrect item being purchased are considered buyer error.
Returns due to 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.