Mikuni Racing – TMX 38mm #TM38-18 Carburetor – 250cc Race Engines (47mm Spigot). Genuine Mikuni.

The TMX carburetor is designed with smooth bore venturi, enhancing throttle response and delivering a broader power band. Its innovative float system, featuring independently moving floats and a main jet housed in a baffle chamber, ensures consistent performance even on the roughest terrain. TMX Series Carburetors come in 35mm bore sizes for 125cc race engines and 38mm bore sizes for 250cc or larger race engines.

TMX35/38mm Carburetors – For Dirt Bikes Road Racing, ATV’s.

The TMX features a flat slide design in a smooth bore venturi to provide improved throttle response and wider powerband. The float system with independently moving floats, working with a main jet enclosed in a baffle chamber, allows the TMX to perform smoothly without hesitation on the roughest terrain. TMX Series Carburetors are available in 35mm bore sizes for 125cc race engines, and in 38mm bore sizes for use on 250cc race engines.

STANDARD SETTINGS

TM35-1

Main Jet – 4/042 – 350

Pilot Jet – VM22/210 – 20

Jet Needle – 6EN11-53

Throttle Valve – 999-832-014-6.0
*(Kit No. TMX35-1-k)

TM38-18

Main Jet – 4/042 – 370

Pilot Jet – VM22/210 – 20

Jet Needle – 6EJ12-55

Throttle Valve – 99-832-014-3.5
*(Kit No. TMX38-18-k)

TM38-27

Main Jet – 4/042 – 370

Pilot Jet – VM22/210 – 20

Jet Needle – 6EJ12-55

Throttle Valve – 999-832-014-3.5
*(Kit No.TMX38-27-k)

*NOTE: COMPLETE KIT INCLUDES AIR BOOT ADAPTER, INNER
THROTTLE CABLE WIRE, CABLE END, MAIN JETS, PILOT JETS,
JET NEEDLE, CLAMPS, HOSE AND INSTRUCTIONS.

IMPORTANT TUNING CHARACTERISTICS

JET NEEDLE

The Jet Needle is the tapered rod that is positioned in the throttle valve by the ‘E’-Clip. The taper
of the needle increases the clearance between the Jet Needle and the fixed Needle Jet outlet as the
throttle is opened. As the air flow volume increases past the throttle slide, the fuel volume is also
increased to maintain the correct air/fuel ratio.

NEEDLE ‘E’-CLIP POSITION
The position of the ‘E’-Clip in the Jet Needle is used to correct or change the air/fuel ratio between 1/4th
and 3/4th throttle valve position. The ‘E’-Clip can be raised or lowered on the Jet Needle.To richen the fuel mixture the ‘E’-Clip is lowered on the Jet Needle, raising the Jet Needle. To lean the fuel mixture the
‘E’-Clip is raised on the Jet Needle.

JET NEEDLES
To correct the fuel mixture at 1/8th to 1/4th throttle slide position it may be necessary to change the Jet
Needle. The Jet Needle will have a series of numbers stamped on it. Example: 6EJ12-55. The numbers 55 indicate that the outside diameter (O.D.) of the Jet Needle is 2.55mm. A smaller O.D. number gives a richer mixture. A larger O.D. number gives a leaner  mixture.

Typical Jet Needles available:

TMX35 
6EN11-58 Leaner
6EN11-57
6EN11-56
6EN11-55
6EN11-54
6EN11-53
6EN11-51 Richer

TMX38
6EJ12-60 Leaner
6EJ12-59
6EJ12-58
6EJ12-57
6EJ12-56
6EJ12-55
6EJ12-54
6EJ12-53 Richer

Note: Mikuni TMX Series Carburetors are intended for off-road riding and racing use only. Not legal for sale or use in California or other locations where similar pollution laws may apply.

Special Order. This item drop-ship-able from Mikuni American. Please inquire for current availability and lead times.

Authorized Mikuni Distributor