Yamaha YZ250F & YZ450F DEF Racing Secondary Dual Injector Kit (BACKORDERED W/ETA 1/10/26)

Description

The DEF Racing Yamaha YZ250 and YZ450 Dual Injector (aka: Secondary Injector) was developed to refine engine response and improve power throughout the entire RPM range. This style injection system utilizing a shower type injector gives the rider a more connected feel to the crankshaft and rear wheel. These kits are designed for durability and hundreds of hours of abuse.

Kit designed to work with:

• 2024-2026  YZ250F
• 2023-2026 YZ250F

Note:

• Airboot not included unless specified. We recommend the 2023-current YZ450 airboot with the 2024-current YZ250F. The YZ450 airboot when installed on the YZ250 greatly improves low end power.
• The 24-current 250 airboot is not compatible with the 450 engine/chassis due length

Kit Includes:

• CNC Fuel Rail Kit
• Quick disconnect ‘T’ fitting
• Bosch MS Fuel Injector (237g/min, 340cc FR)
• High Pressure Fuel Line and OEM Fuel Clamps
• Injector Wiring Harness to Connect to ECU (Please specify ECU type when ordering)
• High-Quality Stainless-Steel Hardware
• Airboot adapter – YZ450 airboot to YZ250 engine throttle body adapter (when using the yz450 airboot on the yz250 engine)

An aftermarket ECU is required for the second injector harness connection (i.e., Vortex, GET, AIM). A calibration to suit your engine specification is also necessary. We offer ECU re-flashing and custom dyno tuning services for your machine.