Mercury Marine 305 / 350 / 377 / 383 ECM Conversion Calibration

MERCURY MARINE SMALL BLOCK
ECM CONVERSION CALIBRATION SERVICE

The Whipple Mercury Marine Small Block ECM Conversion Calibration Service is designed for compatible 305, 350, 377, and 383 engine applications using the PCM555 controller platform. It is most commonly used when repowering a boat from a smaller-displacement Mercury Marine engine to a larger compatible engine package, while also supporting other compatible conversion combinations when the complete application is properly matched.

Proper calibration depends on more than the replacement engine alone. The current engine application, replacement engine application, drive configuration, fuel requirement, and calibration type must all be identified so the ECM can be calibrated for the complete setup.

Application & Calibration Options

When ordering, select the current ECM application and new ECM application from the supported 305 MPI, 350 MPI, 377 MPI, and 383 MPI choices. Both the current and new drive configurations must also be identified as Alpha, Bravo, or Inboard.

Two calibration types are available through this product:

• Stock, 87 Octane - for supported stock engine combinations using 87-octane fuel
• Stage 1, 91 Octane - for supported Stage 1 combinations using 91-octane fuel

Calibration Service Process

The ECM must be removed and sent to Whipple Superchargers for calibration service. Include a copy of the receipt and the requested engine, boat, drive, fuel, and setup information with the ECM. Typical turnaround time is 7-10 days.

New ECM units may be available upon request. Additional calibration support may also be available for certain modified or non-standard engine combinations; contact Whipple before ordering if the application falls outside the available Stock 87 Octane or Stage 1 91 Octane selections.

Application note: Confirm the current ECM application, new ECM application, current drive configuration, new drive configuration, fuel requirement, calibration type, and any engine modifications before ordering. This is a calibration service and does not diagnose or repair mechanical, fuel system, ignition, sensor, or general running issues.