MerCruiser produces a line of inboard, outboard and drive systems for motor boats. When starting these engines first in the morning or after they have been sitting for some time, you will probably need to increase the amount of gas entering the MerCruiser cylinders. This is accomplished by adjusting the "choke" on the MerCrusier engine. The choke on a motorboat engine enriches the air/gas mixture that enters the cylinders. The added gas makes the starting of the engine easier.
Tilt the motor so the drive system is fully submerged in water. Open the tank vent or turn the engine compartment blower fan on.
Place the gearshift in neutral and set the choke lever between half and full. Place the throttle to the "Start" position.
Pull the manual start cord or press the start button.
Slowly adjust the choke lever back to the "Off" position as the engine warms up. As the engine continues to idle, if the choke is left engaged, the engine will start to sputter or will be running rough.
- motor boat image by Wimbledon from Fotolia.com