DYNOJET Jet Kit - Yamaha YFZ450 Q438

Carburetor tuning is critical to extracting maximum performance from your YFZ450, and a mismatched jetting setup will cost you power, throttle response, and reliability. The DYNOJET Jet Kit Q438 delivers precise fuel mapping across your entire powerband, whether you're running stock internals or pushing toward race-spec modifications. With fully adjustable stages, you get the performance gains you need—without guessing or costly dyno sessions.

This kit is engineered specifically for the Yamaha YFZ450, ensuring fitment and compatibility without fabrication. Choose your stage based on your build: Stage 1 delivers a modest 5% bump for stock setups, Stage 2 adds 8% with mild modifications, Stage 3 reaches 10-15% for aggressively modified motors (race-only), and Stage 7 is reserved for high-RPM track use where street drivability doesn't matter. Every stage optimizes both power and throttle response, so you're not just gaining numbers—you're gaining usable performance.

• Yamaha YFZ450 specific fitment
• MPN: Q438
• Fully adjustable jetting stages
• Stage 1: +5% power increase
• Stage 2: +8% power increase
• Stage 3: +10-15% power increase
• Stage 7: Race-only configuration
• Improves throttle response
• Bolt-on installation
• Compatible with stock and modified filters
• Compatible with stock and modified pipes