Installing A Jack Plate: A Step-By-Step Guide For Boat Owners

Jack plates are a device that attaches to the transom of a boat, allowing the motor to be raised or lowered. They are particularly useful for hunters and anglers who may find themselves in shallow waters. Jack plates give you control over your outboard's position, which helps you get better performance from your boat in any operating condition. They can be made from aluminium and resemble a small platform with a hydraulic pump system or manual adjustment. There are three types of jack plates: fixed, manual, and hydraulic. This article will cover the steps involved in putting a jack plate on a boat.

Choosing the right jack plate for your boat

Jack plates are a great accessory to have on your boat, giving you control over your outboard's position and optimising performance. They can be particularly useful when navigating shallow waters, as they allow you to raise your motor and keep the propeller clear of the ground, reducing turbulence.

There are a few key considerations when choosing the right jack plate for your boat:

Type of jack plate

The two main types of jack plates are manual and hydraulic. Manual jack plates are typically cheaper and use a large screw mechanism to adjust the height of the outboard. They may be more time-consuming to adjust and require more effort. Hydraulic jack plates, on the other hand, offer more flexibility and can be adjusted on the fly with the push of a button or a lever. They are usually more expensive.

Setback

The setback is the distance the jack plate extends past the transom. This is important as it affects the leverage the motor has on the boat and the position of the propeller in relation to the turbulent water coming off the hull. There is no set rule for how much setback you need, as it depends on factors such as the amount of bow lift required and the clearance needed. However, as a general rule, you want your motor cavitation plate to be slightly above the bottom of your boat transom to avoid dragging in the water, which can cause spraying and a loss of RPMs.

Coating

The coating of your jack plate is important, especially if you operate in saltwater or brackish water. Here are some common coating options:

• Raw aluminium: While it corrodes more slowly than steel, raw aluminium corrodes quickly in brackish and saltwater. It is a budget-friendly option for freshwater use.
• Black powder coating: This baked-on paint creates a glossy finish but does not protect against corrosion and can chip over time. It is suitable for freshwater use and preferred for fishing and waterfowl hunting due to its non-reflective surface.
• Clear and black anodized aluminium: Anodizing creates a hardened, corrosion-resistant layer on the surface of the aluminium. Clear anodized aluminium has improved corrosion resistance and is suitable for brackish water, while black anodized aluminium offers even better protection against saltwater corrosion.

Horsepower and engine size

The horsepower and size of your engine will also determine the size and type of jack plate you need. For smaller engines with less than 40 HP, mini jack plates or 40 HP and up jack plates may be suitable, depending on the bolt pattern. For larger engines, a heavier-duty jack plate may be required.

Boat size

The size of your boat can also be a factor in choosing a jack plate. As a general rule, longer boats may require a larger setback to position the outboard farther away from the transom, while smaller boats may favour smaller setbacks.

Ease of use and adjustability

Finally, consider how easy the jack plate is to use and adjust. Hydraulic jack plates offer more flexibility and can be adjusted on the fly, making them a popular choice for various boat types. Manual jack plates may require more effort and time to adjust but can still be adjusted on the water.

Preparing for jack plate installation

Before installing a jack plate, there are several steps you should take to ensure a smooth process and optimal performance. Here is a comprehensive guide to help you prepare for the installation:

• Gather the necessary tools and materials: Ensure you have access to the required tools and materials, including a drill and drill bits, sealant tape and silicone sealant, and stainless-steel bolts of suitable size and length.
• Choose the right jack plate for your boat: Consider the size and weight of your boat when selecting a jack plate. Consult a professional to choose a jack plate that suits your boat's specific needs. Take into account the motor horsepower and the size of your boat when determining the setback and height of the jack plate.
• Inspect the mounting surface: Ensure that the mounting surface on the transom is clean and free from debris. Carefully inspect the transom for any cracks or damage that could affect the installation.
• Check bolt and screw compatibility: Ensure the bolts and screws used in the mounting process are of high quality and compatible with the boat's material. This is crucial for the safety and durability of the installation.
• Ensure even weight distribution: Verify that your boat's weight distribution is even before beginning the installation. An uneven weight distribution can impact the boat's balance and performance. Make any necessary adjustments to ensure a balanced weight distribution.
• Tilt the motor upward: Before starting, tilt your boat's motor fully upward to provide ample clearance around the jack plate. This will make the installation process easier and help prevent any accidental damage.
• Follow manufacturer's instructions: It is important to carefully follow the manufacturer's instructions during the installation process. Refer to the provided manual for specific guidelines and recommendations. Ensure that all parts are secured appropriately according to the instructions.

By following these steps, you will be well-prepared for the jack plate installation process, ensuring a smooth procedure and optimal performance for your boat.

Measuring and positioning the jack plate

First, you need to measure and mark the desired position of the jack plate on the transom. This step will help you determine the correct height and setback for your specific application. It is important to ensure that the jack plate is aligned straight with the transom. Take precise measurements and mark the position accordingly.

When measuring and positioning the jack plate, consider the size and weight of your boat, as well as the motor horsepower. The setback and height of the jack plate should be proportional to these factors. Consulting a professional or referring to the boat manufacturer's recommendations can help you make an informed decision.

Additionally, before beginning the installation, ensure that the mounting surface is clean and free from debris. Inspect the transom for any cracks or damage that may affect the installation. It is also crucial to use high-quality bolts and screws that are compatible with the boat's material to ensure a secure and safe installation.

Once you have completed the measurements and marked the desired position, you can proceed to the next step of drilling holes in the transom for the mounting bolts. This will allow you to securely bolt the jack plate to the transom using the hardware provided by the manufacturer.

By following these detailed instructions for measuring and positioning the jack plate, you can ensure a more accurate and successful installation, optimizing the performance and functionality of your boat's jack plate.

Mounting the jack plate to the transom

To mount the jack plate to the transom, you will need to follow these steps:

First, ensure that you have all the necessary tools and materials. This includes a drill and drill bits, sealant tape and silicone sealant, and stainless-steel bolts of suitable size and length. It is crucial to choose the right jack plate for your boat, taking into account the size and weight of your vessel, as well as the proportional setback and height of the jack plate to your boat's size and motor horsepower. Consulting a professional for advice is highly recommended.

Next, prepare the mounting surface by cleaning it and ensuring it is free from debris. Inspect the transom for any cracks or damage, and make sure that the bolts and screws used are of high quality and compatible with the boat's material. Check your boat's weight distribution to ensure it is even, as an uneven distribution can affect the boat's balance and performance.

Now, you can begin the installation process. Measure and mark the position where you want to install the jack plate, ensuring it is aligned straight with the transom. This will help you determine the correct height and setback for your application.

After determining the correct height and setback, it's time to drill holes in the transom for the mounting bolts. Use a drill to create holes that align with the jack plate's mounting hardware. Then, following the manufacturer's instructions, bolt the jack plate to the transom using the provided hardware. Ensure that the bolts are long enough to pass through the transom and jack-plate mounting surface, and apply marine sealant to the mounting holes to prevent leaks.

Finally, tighten the mounting bolts to the recommended torque specifications. Starting with the jack plate at its lowest position, verify full steering travel through the entire trim range. Check for any interference by carefully tilting the engine and paying close attention to components such as the steering cylinder, tie bars, steering hoses, engine rigging, and the outboard itself. If any interference is detected, add a tilt-limiting device or adjust the motor to a higher set of mounting holes.

Adjusting the height and setback

To adjust the height of a manual jack plate, follow these steps:

• Mark the current height of the jack plate with a pencil for reference.
• Level your boat and measure the distance from the pad to the floor, and then from the centre of the propeller to the floor. The difference is the pad-to-prop height.
• Loosen any supporting bolts on either side of the jack plate to allow vertical movement.
• Support the engine to reduce the weight on the bolts and prevent binding during adjustment.
• Turn the centre bolt to raise or lower the jack plate and engine.
• Tighten the bolts and test the performance.

For a hydraulic jack plate, the height is adjusted using a lever or button to engage the pump and pistons to move the engine up or down.

When adjusting the height, it's important to find the right balance between speed and stability. Raising the jack plate can improve speed and fuel efficiency by reducing drag, but if raised too high, it can decrease stability and control.

To adjust the setback, which is the distance the jack plate extends past the transom, consider the amount of bow lift needed and the clearance required to avoid interference with other components. A larger setback can improve planing speed and reduce bow rise, but too much can decrease stability and cause porpoising. It's recommended to refer to similar boats from builders for guidance on the optimal setback.

Frequently asked questions