The alignment of your outboard engine plays a crucial role in the way the boat performs on all speed ranges. An eccentric aligned motor, too high or too low can hurt speed and response rotation. Improperly aligned engines can also result in excessive engine wear and failure and increased fuel consumption. Several adjustments to the motor position determine how it delivers maximum torque and response. Test your boat to determine how it handles, then adjust the engine to bring it within maximum performance tolerances. You can even buy a new outboard motor for bass boat to skip this troubleshooting.
- The trailer of the boat and park it on a hard and flat surface. Place a balanced level of the bubble on the transom. Use a jack to lift the trailer frame to level the cross member. To check your engine support position against the centerline of your boat’s transom, use a tape measure to record the distance from one end to the other. Write the number. Divide the amount in half and mark this position with a felt pen on top of the transom rail.
- Glue a string with a weight on the end of it and hook it to the mark. The width of your transom bracket should be evenly distributed over both halves of the chain. Adjust your engine support clamps to center your engine. Rotate your engine perpendicular to the transom surface to see if the propeller shaft aligns with the bottom of the weighted chain. If the propeller shaft does not match, adjust your engine mount accordingly.
- Rotate the engine, using the tiller handle or steering wheel, through it, full rotation left and right. There should be equal clearance on both sides when the engine reaches full stop on both sides of the transom plate or plug. Adjust the jack plate or shim one of the claw motors to align it. Check that the cavitation plate is horizontal with the lowest part of the hull. Adjust the support brackets or bolts on the jack plate to correct.
- Launch the boat in the water and start the engine. Leave the engine idle while inspecting the lower drive unit and propeller. The water outlet port of the smaller unit should sit at least one inch above the water line to avoid restriction and overheating. The depth of the smaller group should allow the water intake ports to be submerged at least three inches underwater. you can read our how to maneuver a twin-engine boat article to know more.
- Take the boat and open the throttle gradually. Look at the profile of the bow and if it is pointing up or down. Some lift-up will be normal until the boat reaches planing speed; Then the bow will dive down and the boat will increase the speed dramatically. If the boat continues to climb into a bow position and fails to reach the plane, adjust your trim either electrically or manually.
- Bring the bottom of the motor inward to the rear to reduce the excessive arc profile. To adjust electronically, activate the dashboard control switch for the trim “in” position. For manually adjusted motors, remove the motor support bolt with the quick release pin, tilt the engine for the lower unit closer to the crosshead position and replace the spindle. For manual adjustment, try one adjustment hole at a time.
- Notice if the bow points down and stays down while increasing the throttle to maximum speed. If the bow “plows” in this mode and fails to allow the hull to plane, it means that the trim has been set too far in. Adjust an electrical trim using the dash control switch to adjust the trim further away from the engine. For a manual tuning engine, pull the quick release pin on the engine mount and move the engine one step further away from the crosshead.