Transom Screw Thread Sizes For Yamaha Outboard Motors

The transom is the vertical section at the rear of a boat's hull, and the screw thread size of a Yamaha outboard motor's transom is an important consideration when mounting the motor. The standard bolt size for most brands is 1/2 diameter fine thread, but some Yamaha motors use smaller diameter bolts. It is important to check the diameter required by the engine. In addition, the direction in which the bolts are mounted may be specified by the manufacturer and should be followed to avoid damage to the boat or motor.

Transom clamp screw and handle kits for 2/4 stroke Yamaha outboard motors

Transom clamp screw and handle kits are essential for maintaining your Yamaha outboard motor. These kits typically include a clamp bolt screw, plate swivel, and cap, providing you with all the necessary components to update your transom clamp screw.

When it comes to Yamaha outboard motors, you can choose from a variety of transom clamp screw and handle kits compatible with 2-stroke and 4-stroke engines. Here are some options:

Dolity 6E0-43118-00 OMC Clamp Bolt Screw & Handle Kit

This kit is specifically designed for Yamaha 2-stroke and 4-stroke outboard motors. It includes the clamp bolt screw, plate swivel, and handle, allowing you to securely attach the motor to the transom. However, some customers have reported issues with the size, stating that it does not match the threads on their Yamaha motors. Therefore, it is essential to carefully check the sizing before purchase.

ITACO Boat Motor 6G1-43116 6E0-43118 648-43114 Clamp Screw Set

The ITACO Boat Motor Clamp Screw Set is an aftermarket solution for Yamaha outboard motors. It comes with the handle, screw, and pad, as well as a swivel pin with 5/8" UC size threading, which is equivalent to approximately 15.85 mm. This kit has received mixed reviews, with some praising its solid build and functionality, while others have encountered issues with incorrect sizing.

Amazon Basics Clamp Screw & Handle Kit

Amazon offers a clamp screw and handle kit that serves as a direct replacement for Yamaha outboard motors. It includes all the necessary components to secure the motor to the transom. This kit is a good option if you need a quick and easy solution, as it offers fast and free delivery through Amazon Prime.

Usvehj 433675 Outboard Motor Transom Clamp Screw & Handle Assembly

While this kit is primarily designed for Johnson and Evinrude outboard motors, it may also fit similar Gale and Sea King motors. It is made of high-quality steel, aluminum, and plastic, offering durability, corrosion resistance, and anti-rust performance. This kit includes the clamp bolt screw, plate swivel, and cap, ensuring you have all the necessary components for installation.

When selecting a transom clamp screw and handle kit for your Yamaha outboard motor, it is crucial to verify the compatibility and sizing to ensure a proper fit. These kits provide the necessary hardware to securely attach your motor to the transom, so always refer to the specific motor model and year to make an informed decision.

Transom clamp bolt bradding

The transom clamp bolt is an essential component for securing your outboard motor to the boat's transom, and it's important to get the bradding just right to ensure a safe and secure fit. Here's a comprehensive guide to help you through the process:

Understanding the Transom Clamp Bolt

The transom clamp bolt plays a crucial role in mounting your outboard motor to the transom, which is the vertical section at the back of your boat. This bolt, along with the transom clamp, provides a secure and stable connection between the motor and the boat. It's important to use the correct bolt size and follow the proper bradding procedure to ensure a safe and long-lasting installation.

Yamaha Outboard Motor Transom Screw Thread Size

When it comes to Yamaha outboard motors, the transom screw thread size can vary depending on the specific model. However, a common size for the transom clamp bolt is 5/8" UC, which translates to approximately 15.85 mm. It's important to verify this size for your particular motor, as using the correct bolt size is essential for a secure fit.

Gathering the Right Tools and Materials

Before you begin the bradding process, make sure you have the following tools and materials on hand:

• Transom clamp bolt: Ensure you have the correct size and type of bolt for your Yamaha outboard motor.
• Washers: Washers are used to distribute the load and provide a larger bearing surface.
• Nuts: You will need nuts that correspond to the size of your transom clamp bolts.
• Marine lumber: A piece of marine-grade lumber can be used on the inside of the transom to distribute the load and provide additional support.
• Silicone: Applying silicone to the bolts and around the holes can help create a watertight seal.
• Drill: If you need to drill additional holes, ensure you have a drill that can create holes of the appropriate size.

Step-by-Step Bradding Process

Now, let's walk through the step-by-step process of bradding the transom clamp bolt:

• Preparation: Start by gathering all the necessary tools and materials mentioned above. Clean the transom area and ensure it is dry.
• Positioning: Place the outboard motor on the transom, aligning the transom clamp and bolt holes.
• Drilling (if necessary): If your motor has provisions for both transom clamps and bolts, and you choose to use bolts only, you may need to drill additional holes in the transom.
• Assembly: Insert the transom clamp bolts through the holes in the transom and motor. Secure them with washers and nuts. Ensure the bolts are tight and secure.
• Silicone application: Apply a bead of silicone around the bolts and holes to create a watertight seal.
• Testing: Once the silicone has dried, test the installation by taking your boat out for a short ride and checking for any signs of movement or looseness in the motor.

Tips and Best Practices

To ensure a safe and long-lasting installation, keep the following tips in mind:

• Always refer to your Yamaha outboard motor's manual for specific instructions and recommendations.
• When drilling holes, use a drill bit that is appropriate for the material of your transom.
• Apply a liberal amount of silicone to help prevent water ingress and corrosion.
• Regularly inspect the transom clamp bolts and silicone seal to ensure they remain tight and intact.
• If you're unsure about the installation process, consider seeking assistance from a marine mechanic or experienced boater.

In conclusion, bradding the transom clamp bolt is a straightforward process, but it requires attention to detail and the use of appropriate tools and materials. By following the steps outlined above, you can securely attach your Yamaha outboard motor to your boat's transom, ensuring a safe and enjoyable boating experience.

Transom clamp bolt replacement

This guide will take you through the process of replacing the transom clamp bolt on a Yamaha outboard motor. The transom clamp screw, also known as the clamp handle screw, is an essential component for securing your outboard motor to the transom of your boat.

Step 1: Gather the Right Parts

Before beginning the replacement, ensure you have the correct parts for your Yamaha outboard motor. The clamp screw size is an essential factor to consider. The standard size for Yamaha outboard motors is 5/8" UC threading, which is equivalent to approximately 15.85 mm.

Step 2: Prepare the New Screw

The new transom clamp screw may require some preparation before installation. In some cases, you may need to attach a washer to the end of the screw. This can be achieved by placing the flat end of the screw in a vice, installing the washer, and then gently hammering the end to flatten it and secure the washer. Alternatively, you can trim off the end of the screw, drill a hole, and insert a small screw to hold the washer in place.

Step 3: Remove the Old Screw

To remove the old transom clamp screw, you may need to cut off the cups or any damaged parts. Be sure to have a suitable container to catch any falling parts and a clean workspace to avoid losing the small components.

Step 4: Install the New Screw

With the new screw prepared, it's now time to install it. Carefully insert the screw through the mounting clamp hole, ensuring that the washer is securely attached. Tighten the screw, following any specific torque specifications for your Yamaha outboard model.

Step 5: Test and Enjoy

Once the new transom clamp screw is securely in place, test the stability and security of your outboard motor. Ensure that the clamp screw is tight and that the motor is firmly attached to the transom. Now, you can confidently enjoy your boating adventures with a safe and secure Yamaha outboard motor.

Please note that this guide provides a general overview, and specific procedures may vary depending on your Yamaha outboard motor model and the exact nature of the screw replacement task. Always refer to the owner's manual or seek advice from a qualified marine mechanic for detailed instructions specific to your Yamaha outboard motor.

Transom clamp pad attachment

Step 1: Gather the Right Parts

Before you begin, ensure you have the correct clamp screw assembly set. The thread size for Yamaha outboard motors is typically 5/8" UC, which equates to approximately 15.85 mm. You can purchase these screws as part of a kit, which should also include a handle, a plate swivel, and a pin.

Step 2: Prepare the Transom

Inspect your boat's transom to ensure it is solid and in good condition. If needed, you can use a shim to raise the engine slightly, but this is not necessary if the full round pad of the clamp will be in contact with the transom. For motors above 25 HP, consider using transom bolts for added security.

Step 3: Attach the Clamp

Position the clamp so that it sits securely on the transom. The clamp pads should be centred on the transom plate, with the full round pad of the clamp in contact with the transom. You can adjust the position of the inner and outer plates to match the contour of the transom and ensure a snug fit.

Step 4: Secure with Screws

Use the clamp screws to securely fasten the clamp to the transom. Ensure that the screws are tight and will not slip. Depending on your setup, you may also need to attach a safety chain or cable to provide additional security and prevent the motor from jumping during hard turns.

Step 5: Optional Enhancements

You can enhance the tightness of the clamp against the plate by gluing a piece of rubber, tire bladder, or PVC fabric on the inside of the plate. This will help ensure a secure fit. Additionally, consider using a transom mounting plate to protect your RIB/Boat transom from any potential damage caused by the clamp screws. These plates are typically made of tough, lightweight, non-corroding aluminium and can be purchased separately.

By following these steps, you can securely attach the transom clamp pad for your Yamaha outboard motor, ensuring a safe and enjoyable boating experience.

Transom bolt size and spacing

The transom bolt size and spacing will depend on the make and model of your boat and engine.

For example, for a 1998 201 pro elite Stratos/Javelin boat, the standard transom bolts are 4.5 inches long with a 0.5-inch fine thread and brass nylock nuts. However, one user replaced the aluminium sheet cover with stainless steel and needed to use 5.5-inch bolts as a result.

Another user with a 1989 Montauk 17 and a 1989 Yamaha 90 ELTF reported that the thread size of the blind holes in the engine mounting bracket was 12mm diameter x 1.25 pitch. The length of the machine screw will depend on the thickness of the transom.

When purchasing parts for your boat, it is important to check that they are compatible with your specific make and model. For example, one user with a 1986 Yamaha 50ELJ reported that the Dolity 6E0-43118-00 OMC Clamp Bolt Screw & Handle Kit did not have the correct-sized threads for their motor.

It is also important to note that some bolts may be oversized. For example, the ITACO Boat Motor 6G1-43116 6E0-43118 648-43114 Clamp Screw Set for Yamaha Outboards has an American size of 5/8"UC, which is approximately 15.85mm.

Frequently asked questions