Ventilation plates: The air flow or anti-cavitation plate stops the propeller from ventilating or sucking in air, minimizing cavitation and ensuring dependable drinking water circulation. In a very nutshell, the mid-section connects the powerhead and reduce unit and is what attaches the motor for the boat. Where's the cut-off place? https://cheapoutboardsmotorsforsa27260.answerblogs.com/28586738/5-tips-about-outboard-motor-boat-for-sale-you-can-use-today