Kawasaki KLX 650 | Mikuni TM42-6 | Flatslide Pumper Carb kit

Mikuni TM42-6 40mm Flatslide Pumper Carburetor Kit – Kawasaki KLX650

Unlock serious performance on your Kawasaki KLX650 with this genuine Mikuni TM42-6 40mm pumper flatslide carburetor kit. Say goodbye to hard starting, hesitation, flat spots, and sluggish response—experience crisp, instant throttle snap, dramatically improved acceleration, increased horsepower and torque, and effortless wheelies in higher gears.

This bolt-on kit is engineered for maximum power and reliability, delivering the best carbureted performance available for the KLX650.

Key Features & Included Components:

• Genuine Mikuni TM42-6 40mm flatslide pumper carburetor
• Pre-jetted for KLX650 applications (with spare main jets included for fine-tuning during wide-open throttle testing)
• 260mm cable-operated choke with universal mounting bracket
• New throttle cables and 1/4-turn quick-action throttle assembly
• Anodized 58mm silver step-down sleeve to match stock 58–60mm airbox spigot diameter and replicate original carb length (~100mm)
• Detailed tuning support via phone or email after purchase

Important Fitment & Installation Notes:

• Two KLX650 frame variations exist:
• Electric-start KLXC models (as pictured): No overhead crossbar behind the engine—direct fit with minimal modifications.
• Models with overhead crossbar (under the tank): Crossbar must be modified or relocated for clearance.
• Tank modification required on most models: Depress the tank approximately 5mm in the area shown in the photos (easiest with a ball-peen hammer). Optionally, grind a few millimeters off the top of the cable bracket to reduce the amount of tank denting needed. See photo gallery for exact modification guidance.
• Intake flange preparation: The Mikuni TM42 has a 46mm outer diameter—perfect match for the motor flange. Remove (cut off) the locator lugs on your rubber flange to allow full insertion and proper sealing.
• Airbox considerations: Airbox modification may be necessary for optimal performance. During wide-open throttle (WOT) testing, if removing the airbox access cover improves power, drill or cut additional inlet holes in the cover to match flow with/without the cover in place.
• Stock throttle cables are replaced by the included quick-action setup—no compatibility issues.