Mercury Marine MCM 4.3L / MCM 4.3L EFI — Water Testing New Engines

Operation

For the Mercury Marine MCM 4.3L / MCM 4.3L EFI, from the Mercury Marine service manual.

Procedure

1. Start engine and run at idle rpm until normal operating temperature reached.
2. Run boat up on plane.
3. Advance engine rpm in 200 rpm increments to maximum rated rpm.
4. Do not run at maximum rpm for more than 2 minutes.

Source: Mercury Marine service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

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