Honda XR 250 Mikuni TM33 Pumper Carb Kit

This kit is designed for seamless installation on models from 1996 onward that feature a box section frame. However, it may encounter some interference between the tank and frame on earlier models equipped with a round tubular frame. When fitting this kit to earlier models, users may experience a slight carburetor offset to one side, necessitating the heating and gentle depression of the Poly tank for adequate clearance (for a detailed example, refer to our Honda XR650R TM42-6 Pumper carb kit product description). The performance enhancements significantly outweigh any minor inconveniences encountered during installation.

For the 47mm air box intake: Earlier models of the Honda XR250, which utilize a mechanically operated slide-type carburetor measuring 40mm in outer diameter and 103mm in length, feature a 47mm inlet at the air-filter end. This carburetor is supplied with a 49mm air-box sleeve, which can be easily fitted over the additional 2mm in spigot diameter using a heat gun or hair dryer.

For the 55mm air box intake: The later model Honda XR250L, equipped with a steel gas tank, as well as the XR250R with electric start and Baja models with the TPS disconnected, or other variants fitted with a CV carburetor (vacuum-operated slide), also measure 40mm in outer diameter and 103mm in length, but have a 55mm inlet at the air-filter end. This carburetor comes with a 54mm sleeve that allows for a straightforward clamping of the air-box inlet down by 1mm.

Achieving high speeds has never been more accessible. These carburetors have long been favored for installation on any 250cc or 300cc engine with sufficient space, as they provide significant improvements in performance and power, along with enhanced throttle response and overall rideability. The results when fitted to the Honda XR250 are nothing short of exceptional, making this a straightforward, ready-to-install kit.

Additionally, the kit includes throttle cables and a 1/4 turn quick action throttle, as the inner wire length of the Honda cables does not match. Jets are also provided, which may need to be installed if the engine runs slightly rich; however, in most cases, it is simply a matter of bolting it on and riding.

Bullet Point Summary:

• Designed for 1996-Onward Models:

  • Seamless installation on models with box section frames.
  • May require adjustments for earlier models with round tubular frames:
    • Slight carburetor offset to one side.
    • Heating and gentle depression of the Poly tank may be needed for clearance.

• Compatibility for Air Box Intakes:

  • 47mm Air Box Intake (Earlier Models):
    • Mechanically operated slide-type carburetor (40mm outer diameter, 103mm length).
    • 47mm inlet at the air-filter end.
    • Includes a 49mm air-box sleeve:
      • Can be fitted using a heat gun or hair dryer.
  • 55mm Air Box Intake (Later Models):
    • Applicable to XR250L (steel tank), XR250R with electric start, Baja models, and others with TPS disconnected.
    • CV carburetor (vacuum-operated slide) measuring 40mm outer diameter and 103mm length.
    • Includes a 54mm sleeve for easy clamping to reduce the inlet by 1mm.

• Performance Enhancements:

  • Significant improvements in power, throttle response, and rideability.
  • Ideal for 250cc and 300cc engines with sufficient space.
  • Delivers exceptional results when fitted to the Honda XR250.

• Complete Kit Includes:

  • Throttle cables.
  • 1/4 turn quick-action throttle (due to inner wire length mismatch with Honda cables).
  • Jets for tuning (may be needed if the engine runs slightly rich).

• Easy Installation:

  • Ready-to-install design.
  • In most cases, simply bolt it on and start riding.