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

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  • Regular price $299.98
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The CRF 300L series of ECU reflashes recalibrates the base fueling and ignition timing to extract the most potential out of your bike. Fueling is remapped everywhere: idle, cruising, transitional, and full throttle. Additionally, the utilization zones of the stock oxygen sensor are redefined to provide the best all-around performance. All these features come together to result in an improvement in the overall vehicle drivability. Each calibration offers different levels of hardware support so be sure to carefully review the minimum requirements below.


This ECU reflash does not support the 38770-K1T-E11 ECM used in the EU. All other regions: North America, Asia, and Australia can be reflashed.

Features of this reflash:

  • More aggressive timing depending on fuel type (91/87)
  • 11,000 RPM rev limiter
  • Base fuel mapping enriched
  • Closed loop fueling zones redefined which allows a better compromise between fuel economy and power
  • Acceleration fuel maps enriched
  • Warm idle raised up to 1500RPM
  • PAIR and EVAP check engine codes removed
  • Deceleration Fuel Cut altered to alleviate On/Off throttle sensitivity

Minimum Required Modifications for STOCK IMPROVED:

  • None – OE bike at minimum

Minimum Required Modifications for STAGE 1:

  • Free Flowing Muffler and Head Pipe (FMF, Yoshimura, Akrapovic, Arrow, Moto X, or similar)

Minimum Required Modifications for STAGE 1.5:

  • All Stage 1 Modifications + CB/CBR300R Camshafts

Minimum Required Modifications for STAGE 2:

  • Free Flowing Muffler and Head Pipe (FMF, Yoshimura, Akrapovic, Arrow, Moto X, or similar)
  • Aftermarket performance camshafts

Optional Mods: 

CORE ECU Option:

Please send me a new ECU = You will receive a new ECU that is already tuned from us, no need to mail in your OE ECU. 

I will send in my own ECU = You need to mail us your OE ECU so we can reflash it.

If you purchased a new ECU from us, you may return your stock unit for a core deposit. The Core Deposit is $129.99 USD. To initiate a return, contact us at Email Support.  

If you are mailing us your ECU, please use the address below:

550Performance LLC
ATTN: ECU Reflash + Order Number
1921 Huckleberry Ave
Omro, Wisconsin 54963

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.

Please be aware that 550Performanc LLC is not responsible for and will not refund any charges incurred upon arrival of our products abroad.
This includes charges such as, but not limited to:

  • Import duties
  • Import VAT
  • Custom fees
  • Warehousing fees
  • Any Parcelforce UK fees
  • Any charges incurred as a result of importing goods ordered from 550Performance LLC

Prices and cost of shipping published on our website does not include any of those charges. When placing an order with 550Performance LLC you agree to take full responsibility for any charges incurred by importing our goods into your country.


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