Your baseline before FAS Marine calibration.
← All Mercury tunesMercury
L4 / L6 performance calibration
Mercury
L6 400
Unlock stronger throttle response and serious horsepower from the engine you already own.
UP TO475HORSEPOWER
01 / POWER LEVELS
Pick your
calibration.
Both stages are model-specific calibrations. Final selection depends on your fuel, hardware, boat setup, and intended use.
+50 HP over factory output with increased response.
+75 HP over factory output. No additional Stage 2 hardware listed.
02 / YOUR SETUP
Know before
you send it.
- Engine
- Mercury L6 400
- Factory output
- 400 HP
- Restrictor plate
- Not listed as required
- Stage 2 hardware
- No additional Stage 2 hardware listed
- Tune price
- $2,299.99
03 / COMPLETE PERFORMANCE PACKAGE
The tune is
the starting point.
$499.99Add to this
engine tune
engine tune
- Custom performance tune
- Lifetime setup support that transfers with the engine
- Prepaid 2-day return shipping
For multi-engine setups, add one Complete Performance Package followed by individual tunes for the remaining engines in the same order.
Mercury L6 400
Ready to unlock
475 HP?
Tune pricing from $2,299.99
Request this tunePerformance figures depend on engine condition, fuel quality, supporting hardware, vessel setup, and operating conditions. Confirm your exact model, serial number, requirements, and intended calibration with FAS Marine before purchase or operation.