MY21+ | ECU Tuning | Honda CRF 300 L and Rally

Product Overview:
550Performance offers a range of ECU tunes designed to enhance the performance of the 2021+ Honda CRF300L. Each tune is optimized for specific fuel grades and modifications, delivering increased power, improved throttle response, and enhanced drivability. Updates include revised fuel and ignition timing tables, adjustments to cold start and idle strategies, and refinements to alleviate the common 5000 RPM engine rattle. Whether you're a casual rider or a performance-focused enthusiast, 550Performance tunes unlock the bike’s true potential.

Key Features:

• Increased power and torque across all tunes
• Engine speed limiter raised to 11,000 RPM
• Adjusted warm idle speed to 1,500 RPM
• Revised fuel and ignition timing tables for optimal performance
• Enhanced throttle response and drivability
• Minimized or eliminated 5000 RPM engine rattle
• Removal of check engine lights for EVAP and PAIR systems
• Smoother deceleration with adjusted fuel cut-off strategy

Hardware Requirements:

How to Use the Tune Matrix

1. Select Your Tune
• Pick the stage that matches your goals (Stock Improved → Stage 4.5).
• Each stage has unique hardware requirements for best performance.
2. Match the Hardware
   • [0] = Required baseline hardware
   • [+] = Recommended upgrade for added performance
   • [-] = Acceptable but reduces performance (not ideal)
   • [X] = Incompatible – do not use
• Use only the components listed in the same row as your chosen tune:
3. Hardware Guidelines by Stage
• Stock Improved → For stock exhaust and simple intake bolt-ons.
• Stage 1.0 → Optimized for intake and exhaust upgrades.
• Stage 1.5 → Builds on Stage 1.0 with CB300R camshafts.
• Stage 2.0 → Builds on Stage 1.0 with Sport camshafts.
• Stage 3.0 & 4.0 → Designed for big-bore kits and camshaft upgrades.
• Stage 3.5 & 4.5 → Maximum performance setup with big-bore, camshafts, and cylinder head work.

Tune Variants & Performance Gains:

• 87/91 Stock Improved Tune | +11% power / +5% torque
• 87/91 Octane Stage 1.0 | +18% power / +12% torque
• 87/91 Octane Stage 1.5 | +23% power / +12% torque
• 91 Octane Stage 2.0 | +30% power / +14% torque
• 91 Octane Stage 3.0 | +34% power / +25% torque
• 91 Octane Stage 3.5 | +39% power / +31% torque
• 91 Octane Stage 4.0 | +45% power / +25% torque
• 91 Octane Stage 4.5 | +52% power / +33% torque

Important Notes:

• ECU reflashes are not compatible with EU-specific ECMs: 38770-K1T-E11, EB1, or EM2
• International customers are responsible for any duties, VAT, or additional shipping charges
• Core ECU deposit program available for $129.99 USD – contact support@550Performance.com for availability
  
• All fuel octanes listed in AKI (R+M)/2 (PON)
• FOR CLOSED COURSE COMPETITION USE ONLY. NOT INTENDED FOR STREET USE.
• NOT LEGAL FOR SALE OR USE ON ANY POLLUTION-CONTROLLED MOTOR VEHICLES.

Mailing Instructions for Mail In Tunes:

550Performance LLC
ATTN: ECU Reflash + Order Number
W3183 Willow Lane
Hilbert, Wisconsin 54129
USA

Upon receipt, we will flash the ECU and send it back to you. Typical turnaround is 1 - 3 business days. In some rare cases this could be as long as 5 business days.

Unleash your CRF300L’s full performance with 550Performance ECU tuning – built for riders who demand more.