(a) Any system installed on, or incorporated in, a new engine to enable the engine to conform to the standards contained in this part:

(1) Shall not cause a violation of the general standards of §94.7.

(2) Shall function during all in-use operation, except as otherwise allowed by this part.

(b)

(1) Category 1 marine engines equipped with adjustable parameters must comply with all requirements of this subpart for any adjustment in the physically adjustable range.

(2) Category 2 and Category 3 marine engines equipped with adjustable parameters must comply with all requirements of this subpart for any adjustment in the approved adjustable range.

(c) The Administrator may require that adjustable parameters be set to any specification within its adjustable range for certification, selective enforcement audit, or in-use testing to determine compliance with the requirements of this subpart.

(d) In specifying the adjustable range of each adjustable parameter on a new engine, the manufacturer, shall:

(1) Ensure that safe engine operating characteristics are available within that range, as required by section 202(a)(4) of the Clean Air Act, taking into consideration the production tolerances; and

(2) To the maximum extent practicable, limit the physical range of adjustability to that which is necessary for proper operation of the engine.

(e) Tier 1 Category 3 marine engines shall be adjusted according to the manufacturer's specifications for testing.

(f) For Category 3 marine engines, manufacturers must specify in the maintenance instructions how to adjust the engines to achieve emission performance equivalent to the performance demonstrated under the certification test conditions. This must address all necessary adjustments, including those required to address differences in fuel quality or ambient temperatures. For example, equivalent emissions performance can be measured relative to optimal engine performance that could be achieved in the absence of emission standards (i.e., the calibration that result in the lowest fuel consumption and/or maximum firing pressure). In this example, adjustments that achieved the same percent reduction in NOX emissions from the optimal calibration would be considered to be equivalent. Alternatively, if the engine uses injection timing retard and EGR to reduce emissions, then retarding timing the same number of degrees (relative to optimal engine performance) and using the same rate of EGR at the different conditions would be considered to be equivalent.

[64 FR 73331, Dec. 29, 1999, as amended at 68 FR 9785, Feb. 28, 2003]