Section R. 281.3104 - Main enginesRule 104.
(1) Each vessel designed for inboard or inboard/outboard (stern drive) main engines shall be fitted with the appropriate number of engines.(2) All main engines shall be of the appropriate type and design for the propulsion requirements of the hull in which they are installed, shall be capable of operating at a constant marine load without exceeding their design limitations, and shall be in good and serviceable condition.(3) The head, block, and exhaust manifold of any main engine shall be waterjacketed and cooled by water from a pump which operates when the engine operates, except for drystack exhaust systems.(4) When a main engine is fitted with an updraft or sidedraft carburetor, the carburetors shall have integral or properly connected drip collectors of adequate capacity which will return all drip and overflow to the engine intake manifold.(5) The exhaust pipe system of the main engines shall comply with all of the following provisions: (a) Be gastight to the hull interior.(b) Be designed and installed to prevent cooling water or seawater from returning to the engines.(c) Be so accessible that it can be inspected and repaired throughout its length.(d) Be supported so as to prevent undue stress which may cause fractures. Hangers, brackets, and other supporting components shall be made of fireproof materials and shall be installed so as to prevent the transmission of heat to adjacent combustible materials.(e) Where personnel or combustibles might come in contact with hot surfaces, effective protection shall be provided by water jacketing, lagging, shielding, or suitable guards.(6) Outboard engines on vessels designed for utilizing outboard engines as main engines shall be in good and serviceable condition.(7) Vessels utilizing unique or unusual machinery as main engines shall be given separate consideration and shall be subject to requirements as determined by the marine inspector after consultation with the state boating law administrator. The requirements shall be in keeping with good marine practice and standards. These unique or unusual types of machinery shall include those utilizing steam, electricity, gas turbines, air screws, and hydraulic jets.(8) When auxiliary engines are installed on a vessel, they shall be installed in accordance with good marine practice and standards and shall be in good and serviceable condition.Mich. Admin. Code R. 281.3104