Pontoon boats are usually very easy to operate. As a luxury vessel designed for calm water usage pontoon boats are intentionally designed to be easy to drive. So, why does a pontoon boat sometimes pull to the right and what can you do about it.
A pontoon boat will pull to the right due to a misalignment of the trim tab on the propeller system. As the propeller turns clockwise in the water the force it generates, the torque, can twist the engine to the left side causing the boat to veer to the right. It can be easily fixed by adjusting the trim tab. This is a small fin located on the prop.
- Why your pontoon boat pulls to the right
- How to adjust the trim tab to stop a pontoon boat pulling right
- How to adjust the trim tab to stop a pontoon boat pulling left
- Why does the boat lean to one side when under power?
- Why it may be best to take the boat out of the water before making changes
Why your pontoon boat pulls to the right
Pontoon boats are built for luxury. This is what makes them so popular. But, luxury does not just mean high-end interior design and on-water creature comforts based around fun activities and relaxation. Luxury in a boat in our modern times also means speed and ease of handling. Therefore a pontoon boat is designed to be easy to drive. So why is it common for many pontoon boat owners to complain about their vessel pulling to the right?
Although a pontoon boat can also pull to the left (more on that later) it is much more common to find the boat pulls to the right. This is due to propeller torque. Propeller torque refers to the twisting force generating by the propeller system.
When the boat is moving forward the propeller will turn in a clockwise direction. The twisting force, the torque, generated by the spinning shaft will automatically cause the boat to turn to the right. In extreme cases the torque can actually cause the entire boat to learn to the right as well making it pull to the right. In instances where the pontoon boat is leaning to the right you may need to swap out your prop for a higher-pitch one but this is only usually necessary if the boat is leaning heavily.
If your pontoon boat is only pulling to the right, and does not significantly lean that way, there is a very easy fix to rectify the problem without having to buy a new higher-pitch prop (which has major drawbacks that I discuss later). Before I discuss this easy-fix you should be aware that there is another potential cause for your boat pulling right.
Another potential cause for a pontoon boat pulling to the right could be the position of the prop when underway. Sometimes you simply need to adjust the trim of the motor while you are driving the boat to offset the pull. This can occur at any time while on the water but will be most pronounced in rough waters when traveling at speed.
So, ask yourself, could your driving technique be to blame or the type of waters you are navigating? Probably not, but it is worth mentioning these less common causes in case you only encounter occasional bouts when the boat pulls to the right. Sometimes the simplest explanation proves to be the accurate one.
Having said that, it is much more likely that the problem of your pontoon boat pulling right lies with its outboard motor. In particular, the problem, and solution, lies in the propeller system. By making a simple adjustment to a small fin-like part of the propeller system you can ensure your pontoon boat always stays on an even course when steering.
The small fin-like appendix on the prop that needs to be adjusted is called the trim tab.
In it fairly common for there to be a slight misalignment in the trim tab, even in an outboard motor that has just left the factory. If you find that your pontoon boat is pulling to the side consistently then it is almost certainly due to this misalignment.
Making the necessary adjustment to the trim tab to offset the pull on a pontoon boat is quick and easy.
How to adjust the trim tab to stop a pontoon boat pulling right
Adjusting the trim tab to stop the boat from veering of course and pulling to the right is a very easy task to complete. Below I have included a video that shows you how to do this but it is really a very simple task.
On the propeller of the outboard motor you will see a small fin-like appendix, the trim tab. Although the trim tab is designed to rotate you will notice that it is is secured in a permanent position via a single bolt nut. By loosening this bolt you can rotate the trim tab and secure it in a different position.
In the image below you can see the location of the trim tab and the bolt nut that holds it in place.
This bolt nut can be easily loosened, to realign the trim tab, via a monkey wrench or similar tool.
Loosen the trim tab and fix it to a central position as demonstrated in the video below. If the trim tab is already centered then follow the additional advice given in the second video.
How to center the trim tab to stop the boat pulling right (video)
For most pontoon boat owners fixing the problem of their boat pulling to right is as simple as just centering the trim tab on the prop.
More likely than not, if your pontoon boat is pulling to the right then when you look at the prop you will likely see that the trim tab is turned towards the left of center.
By loosening the nut you will be able to rotate the trim tab and move it into a center positional before tightening the bolt.
If you find that your trim tab is already centered, or that centering it does not fix your problem, fear not. There is still a way to fix the problem as outlined in the video below.
How to adjust the trim tab if centering it does not work (video)
Sometimes centering the trim tab does not fix the problem. I will not go into the reasonsons for this as it could be any of several potential problems causing the pull. Instead I will simply show you how to fix it.
The video below will show you how to adjust the trim tab to stop the prop from pulling the boat to the side when centering the trim tab doesn’t work for you.
As you can see, when centering the trim tab doesn’t work to eliminate the pull on your pontoon boat you can further offset the pull by simply rotating it more to the right.
Be aware that it may take you several small adjustments before you find that sweet spot where the pull completely disappears.
How to adjust the trim tab to stop a pontoon boat pulling left
Although it is more common for a pontoon boat to pull to the right (for the “torque” reasons I gave above) you may be a boat owner who has a vessel that pulls to the left. The good news is that the fix for a boat pulling to the left is just as easy as the fix for a boat pulling right.
Just as you would do if your pontoon boat is pulling to the right, you will begin by loosening the bolt that holds the trim tab in place on the motor’s prop. But instead of repositioning the trim tab right of center you will turn it to the left. The amount you turn it will take will depend on the strength of the pull. Just as you may have to make several minor adjustments to the trim tab for a right pull, you may have to do the same to fix a left pull.
To see how to do this watch the video above under the section How to adjust the trim tab if centering it does not work as it includes directions for fixing a left pull.
Why does the boat lean to one side when under power?
Does your pontoon boat also lean to the side when it is under power?
The same thing that can cause your boat to pull to one side can also cause it to actually lean to the side as well.
A boat will lean to one side when under power due to propeller torque. Propeller torque refers to the twist-force of the propeller. When the boat is moving forward the propeller will turn in a clockwise direction. Extensive twisting force, torque, generated by the spinning shaft can cause the boat to turn and lean to one side.
When you find that your pontoon boat is leaning to one side, and the boat is loaded properly and within its weight capacity limits, then it is the propeller torque that is mostly likely the cause.
A misaligned trim tab is not the only factor that can cause a boat to lean to one side while underway but it is probably the first thing you should look at. Follow the steps given above for adjusting the trim tab to see if this solves your problem.
If adjusting the trim tab does not stop your boat from leaning to the side when underway then you probably need a new prop. Switching to a higher-pitched propeller will mean an instant lowering of the torque. Unfortunately, this can mean making a trade-off between the added stability, and less lean, with lower acceleration (and in the case of non-pontoon-boats an inability to get on plane).
Also be sure that the load of the boat is not uneven and too heavy on one side. Although not an ideal solution, you can try to make the boat heavier on the opposite side of the lean to offset it, if all other options fail.
Why it may be best to take the boat out of the water before making changes
Although you can fully trim the motor to gain access to the prop I really think it’s best to do this when the boat is on dry land.
For those you you who keep your boat permanently in the water this may prove to be difficult. If you have lifts then you can simply work on the prop with the boat lifted out of the water where you usually dock it as long as this gives you easy access to the propeller.
If you need to make a few minor adjustments to the trim tab to completely eliminate the pull then you will obviously need to do this while out on the water.