Methods of making and operating outboard motors

摘要

An outboard motor and a method of making an outboard motor provide an exhaust conduit having a first end that receives exhaust gas from an internal combustion engine and a second end that discharges exhaust gas to seawater via a propeller shaft housing outlet. An exhaust conduit opening is formed in the exhaust conduit between the first and second ends. The exhaust conduit opening is for discharging exhaust gas from the exhaust conduit to atmosphere via a driveshaft housing of the outboard motor and via an idle exhaust relief outlet and a driveshaft housing outlet in the driveshaft housing. The driveshaft housing outlet is vertically located between the propeller shaft housing outlet and the idle exhaust relief outlet. A cooling pump pumps cooling water from a cooling water inlet for cooling the internal combustion engine to a cooling water outlet for discharging cooling water from the outboard motor. The exhaust conduit opening and cooling water outlet are configured such that the cooling water collects by gravity in the driveshaft housing to a level that is above the exhaust conduit opening.

主权项

1. An outboard motor comprising:
an exhaust conduit having a first end that receives exhaust gas from an internal combustion engine and a second end that discharges exhaust gas to seawater via a propeller shaft housing outlet; an idle exhaust relief outlet that is located vertically higher than the propeller shaft housing outlet on the outboard motor, the idle exhaust relief outlet receiving exhaust gas from the internal combustion engine and discharging the exhaust gas to atmosphere; an exhaust conduit opening formed in the exhaust conduit between the first and the second ends, the exhaust conduit opening for discharging exhaust gas from the exhaust conduit to atmosphere via a driveshaft housing of the outboard motor and via both the idle exhaust relief outlet and a driveshaft housing outlet in the driveshaft housing, the driveshaft housing outlet being vertically located between the propeller shaft housing outlet and the idle exhaust relief outlet; and a cooling water pump that pumps cooling water from a cooling water inlet for cooling the internal combustion engine to a cooling water outlet for discharging cooling water from the outboard motor; wherein the exhaust conduit opening and cooling water outlet are configured such that the cooling water collects by gravity in the driveshaft housing to a level that is above the exhaust conduit opening.