Honda XR650L | TM40 Flatslide Pumper Carb KIT |

Mikuni TM40-6 Pumper Carburetor Kit – Honda XR600 / XR650

Go fast the easy way. The Mikuni TM40-6 Pumper Carburetor Kit completely transforms the performance of your Honda XR600 or XR650, banishing hard starts, throttle hesitation, bogging, and flat spots for good. This precision-engineered flatslide pumper carb delivers instant, crisp throttle response, noticeably stronger torque, smoother power delivery, and real-world dyno-proven gains of up to 25% more horsepower over stock.

Complete Kit Includes:

• Genuine Mikuni TM40-6 flatslide carburetor with built-in accelerator pump
• Pre-installed silver anodized airbox adapter (designed for stock airbox fitment)
• Pre-installed engine outlet spigot adapter (matches XR intake manifold flange)
• 1/4-turn quick-action throttle assembly with matching throttle cables
• Cable choke installed (plus optional knob choke included for flexibility)
• Main and pilot jets pre-installed, plus a full selection of spare jets for precise tuning

Easy Bolt-On Fitment & Smart Tuning

No fabrication required—this kit is pre-configured and adapter-equipped for a direct, hassle-free install on XR600 and XR650 models while retaining your OEM airbox and intake setup. Fine-tune easily with the included jet range to match:

• Fuel octane and quality
• Altitude and climate conditions
• Engine modifications (cams, exhaust, big bore kits, head porting, etc.)

Key Performance Benefits

• Lightning-fast throttle response with zero lag or lean spots
• Stronger low- and mid-range torque for better trail and dune performance
• Smoother, more linear power across the entire rev range
• Reliable cold starts and elimination of bogging/flat spots
• Mikuni’s legendary durability and race-proven engineering

Whether you’re carving singletrack, blasting desert whoops, or riding fire roads, this TM40-6 pumper kit awakens your XR’s full potential and makes every ride more responsive, powerful, and enjoyable.

Upgrade your Honda XR600 or XR650 today and experience the difference a proper pumper carb makes. Questions on jetting or fitment for your specific build? Reach out—we’re here to help! SpeedMotoCo.com