Every boating veteran seems to be talking about how trimming the outboard motor helps improve the motor performance on the water.
Outboard motor trim positions can indeed make a big difference in your boating experience, and learning how to trim your motor properly is crucial before you get out on the water fishing.
New to boating and struggling with trimming the motor at a certain depth of water?
This post will introduce everything about trimming your outboard motors, including the basics, its benefits, and most importantly, the detailed steps to do it (with a video tutorial).
If you don’t want to waste power with the wrong outboard motor trim position, continue reading for more insights and pro tips about the outboard trimming – You will not miss anything to become an expert on this technic!
Table of Content:
- What Is Outboard Motor Trimming
- Why Trimming Is Important
- Outboard Motor Trim and Tilt Comparison
- Best Outboard Motor Trim Position
- How to Manually Trim Outboard Motor
Before diving into the depth of the benefits, best practices and steps, let’s clarify what outboard motor trimming is.
In simple words, trim is the angle of the propeller shaft in comparison to the boat. According to the outboard motor trim positions, there are three situations you may have heard from the boating community:
- Neutral trim: Standard position where the prop shaft is parallel with the water surface. The outboard motor is parallel to the boat’s transom in a neutral trimming position.
- Positive trim: The angle of the motor is up, and the bow of your boat will rise.
- Negative trim: The angle of the motor is down, and the bow of the boat will drop.
Here is a figure that shows you the different motor trim positions to help you have a better understanding of the trimming position:
To adjust the outboard motor trim position, you will need either to trim up or trim down:
- Trimming up/Trimming out: Tilt the motor upward where the angle of the propeller is facing more downward into the water.
- Trimming down/Trimming in: Tilt the motor backward, making the propeller closer to the boat and face more upward to the water surface.
Trim and Tilt Comparison
Besides the above terms, you may also have heard about the outboard motor tilt and trim. Wondering if tilt and trim the same thing?
They are basically two different stages of the system.
Trimming usually goes about 20 degrees while underway. It’s used to adjust the hull’s attitude to reach the best boating performance. In contrast, tilt raises and lowers the lower unit out of the water for transport or shallow water operation.
For example, the ePropulsion electric outboard motor offers 4 level trimming options (21°, 14°, 7°, and 0°) to help improve its in-water performance, and a tilt angle of 85° to help the outboard stay out of the water or detach it from the boat.
*Some quality electric outboard motors, including the ePropulsion motors, feature an anti-grounding mode which enables the lower unit to be flexible in the trimming or tilting direction.
The flexible trimming will effectively protect the outboard motor from damage when the outboard hits the reefs or rocks underwater.
Trimming is one of the most effective ways to improve the overall experience of your boat.
The logic behind it is simple: The outboard motor trim position affects the boat’s performance by factoring in the boatload.
If you trim up (or trim out) the outboard, the propeller pushes down into the water. Therefore, it pushes the bow of the boat out of the water (as shown in the image below), leaving an angle between the boat and the motor. In this way, it lightens the boatload since there will be less of the lower unit on the water which produces drags.
In this case, trimming on the outboard motor enhances the energy efficiency and speed.
By contrast, if you trim down, the outboard motor propeller will push the bow of your boat into the water (as shown in the image below) and the motor will get close and attach to the boat, increasing the drag between the boat and the water.
In this case, the trimming reduces energy efficiency and speed and increases your cost in the long run. However, this operation can be beneficial when running in choppy water conditions.
Having some knowledge about the uses of outboard motor trimming, your next question would probably be something like “How much should I trim my outboard motor”.
It’s a tricky question because the best outboard motor trim position always depends on the type of your boat, the running speed, and varies based on your boating conditions.
Keep in mind that the correct outboard trim position is what suits at the time, sometimes it might be all the way down, sometimes in the middle, sometimes none of those positions.
There is really no fixed answer – That’s why you need trimming to adjust according to your specific situations.
If your boat is on plane, here are some typical situations just for your reference:
- Trim down in rough water and drive the bow deep into the water
- Trim up a little and let the motor level with the bottom of the hull is the most energy effective outboard motor trim position
- Trim and tilt up if you are passing through shallow waters (or simply adjust to the Anti-grounding mode or shallow water mode if it is available)
If you’re idling and your boat is not on the plane, a rule of thumb is that a boat handles best when it’s running parallel with its at-rest waterline.
Whether over trim or under trim, the outboard motor is not in its optimum thurst and some power is wasted. Here is a figure that helps you understand this.
Tips: Carefully plan the passenger distribution on the deck if you have more than one person on the boat since it will affect the outboard motor propeller positioning underwater.
The best way to get your best outboard trim position is to play and learn. Finally, you will “feel” the hull ride its best at the proper trim.
So how do you adjust the trim tab on an outboard motor? How do you trim the top speed of a boat?
Trimming the outboard motor is easy, and the steps are usually available on the outboard motor user manual. If you have trouble finding the user manual, you may seek help from the local dealers or download the online resources.
Here we take the popular ePropulsion Spirit 1.0 Evo as an example. There are four simple steps to trim the outboard motor manually:
Step 1. Pull the trim release lever up and tilt up the outboard to the 85° position.
Step 2. Remove the pull ring on the trim pin and then pull the trim pin out.
Step 3. Select a desired trim angle and insert the trim pin into the corresponding position, attach the pull ring to fix the trim pin.
Step 4. Pull the trim release lever again to lay down the outboard motor, and the outboard motor will stay at the desired trim angle.
Notice: Make sure the outboard motor is stopped before trimming your outboard motor.
Here is also a video tutorial to show you the steps for manually trimming your outboard motor:
Note: The above steps specifically discuss the smaller electric outboard motors that mostly require manual trimming. Those larger boats featuring higher-powered combustion outboards may have power trim available and this tutorial will not apply in this case.