Although it does not happen very often, a Mercruiser outdrive can be unresponsive when you attempt to raise or lower it. Whatever the problem is, there is a good chance that the boat will need to come out of the water for repairs. When the outdrive trim system is inoperative, the only alternative is to lift the Mercruiser outdrive manually so that no damage occurs when retrieving the boat from the water. While this is a simple operation for two people, one person cannot do it without the risk of personal injury or damage to the boat.
Idle the boat to the boat ramp it was launched from. Back the boat trailer into the water and clip the hook of the wench to the clip hook on the front of the boat hull. Have another person crank the wench to rewind the cable. Stay at the stern of the boat to gauge when the outdrive is in water shallow enough to allow safe removal of the power trim pistons from the outdrive. Instruct the other person to stop rewinding the winch cable at that point and to board the boat.
While the boat is still in the water, remove the nuts on the mounting studs for the power trim pistons using the proper sized box-end wrench from a tool kit. Remove the flat washers that normally sit between the nuts and power trim pistons. Pull the ends of the power trim pistons off the studs.
Tie one end of a rope around the lower portion of the outdrive. Ensure the rope is long enough to reach from the outdrive to a cleat on the deck. Hand the other end of the rope to the person on board.
Grasp the bottom of the outdrive behind the propeller. Pull the outdrive up and hold it until the person on deck ties the rope onto a cleat, completing the manual raising of the Mercruiser outdrive.
Outdrives are very heavy. Use common sense when tilting the outdrive up manually. Use your arms and legs to lift, not your back. When routing the rope between the outdrive and the deck cleat, ensure that the rope will not damage any seating or accessories on the boat.
Do not attempt to lift the outdrive while the engine is running. Damage may occur to the hydraulic system if the power trim pistons are not removed from the outdrive studs before manually lifting it.