Subd. 1. Exhaust muffling system required.

A motor may not be used on a motorboat unless it is equipped with an efficient muffler, underwater exhaust, or other device that adequately muffles or suppresses the sound of the exhaust of the motor so as to prevent excessive or unusual noise. A motor may not be equipped with a cutout.

Subd. 2. Sale of motor that exceeds noise limits prohibited.

A person may not sell or offer for sale a new marine engine or motorboat that would exceed the noise limits contained in section 86B.321, subdivision 2, under a test procedure approved by the commissioner if the motor is maintained according to the manufacturer's specifications.

Subd. 3. Modification of engine to exceed noise limits prohibited.

1. (a) A person may not modify a marine engine or motorboat in a manner that will amplify or increase the noise emitted by the marine engine or motorboat above the noise limits contained in section 86B.321, subdivision 2, under a test procedure approved by the commissioner.
2. (b) A person may not operate a motorboat with an engine modified to increase noise above the noise limits.

Subd. 4. Sale of parts that cause excessive noise prohibited.

1. (a) A person may not sell or offer for sale replacement or additional parts for a marine engine or motorboat which when installed in the marine engine or motorboat will amplify or increase the noise emitted by the marine engine or motorboat above the noise limits contained in section 86B.321, subdivision 2, under a test procedure approved by the commissioner.
2. (b) A person may not operate a motorboat incorporating parts prohibited to be sold under paragraph (a).

Subd. 5. Applicability.

The provisions of this section do not apply to motorboats operating under a permit issued under section 86B.121 or a United States Coast Guard marine event permit in a regatta, or race, while on trial runs, or while on official trials for speed records during the time and in the designated area authorized by the permit.