Unleash the True Power of Your Yamaha V6 4.2L SHO
The Mealey Marine Outboard EFI Mail-In ECU Tune transforms the Yamaha 4.2L V6 SHO (200 / 225 / 250) into a 325-horsepower machine. This calibration unlocks the full performance potential of Yamaha’s top-tier V6 platform—delivering up to +125HP and as much as 15 % better fuel economy—all while maintaining OEM-level reliability and drivability.
Your order automatically includes a prepaid inbound shipping label and packing instructions, so sending your ECU is simple and secure.
Performance Gains
- HP Gain: Up to 325 HP (setup-dependent)
- Rev Limit Increase: From 6150 to ~6500 RPM
- Throttle Response: Sharper and more immediate throughout the range
- Top Speed: Significant gains with the correct prop and load
- Fuel Efficiency: Improved mid-range economy at cruising RPM
Fuel, Compatibility & Supported Models
- Fuel Required: 93 Octane Recommended (91 Minimum)
- Tuneable Years: 2010–Present
- Engines: Yamaha VF200, VF225, and VF250 SHO V6 4.2L
- ECU IDs: 6CD-XX 6LG-XX 6CC-XX 6HB-XX 6KX-XX 6CB-XX 6FR-XX 6LF-XX
- Configuration: DOHC, 6 Cyl, 4.2L (≈4169cc)
Why Tune with Mealey Marine
- Custom calibrations built on proven Outboard EFI software and testing
- Bench-tested read/write process with checksum verification
- 1–2 Business Day Turnaround once your ECU is received
- Backed by Marine Technicians who install, service, and run these engines daily
- Safe, reliable power built for performance fishing and recreational boats alike
How the Mail-In Process Works
- Order this tune. You’ll automatically receive a prepaid inbound shipping label and packing instructions.
- Ship your ECU to Mealey Marine in Houston, TX. Label it with your Order # and include your boat details and fuel grade.
- We tune your ECU using Outboard EFI calibration software, test and verify it, then ship it back to you.
- Reinstall and run. You’ll notice faster holeshot, stronger midrange torque, and higher RPM with stock reliability.
Before You Ship
- ECU should be in good physical condition with matching ID.
- Engines must be mechanically sound and properly maintained.
Results You Can Feel
Expect a crisper throttle, stronger hole-shot, and a boat that feels “lighter” and faster on plane. Customers typically report 2–4 MPH top-end gains and a flatter torque curve that carries load better under real-world conditions.
Questions?
Call or message Mealey Marine — Marine Problem Solvers. We’ll help you confirm ECU compatibility and advise on prop, load, and fuel setup to get the best performance possible.
Liability & Warranty Disclaimer
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