How to replace the field coils in the Yanmar 4JH starter? - Blog

Hey there! As a supplier of Yanmar 4JH starters, I often get asked about how to replace the field coils in these starters. It's a task that might seem a bit daunting at first, but with the right guidance and a bit of know - how, you can do it like a pro. So, let's dive right in and go through the process step by step.

Why Replace the Field Coils?

Before we start with the replacement process, you might be wondering why you'd even need to replace the field coils in the first place. Well, over time, these coils can wear out due to normal use, heat, and electrical stress. When they start to fail, you might notice issues like the starter not engaging properly, slow cranking, or even complete starter failure. Replacing the field coils can often fix these problems and save you the cost of buying a brand - new starter.

Tools You'll Need

First things first, gather all the tools you'll need for this job. You'll need a set of wrenches, a socket set, a screwdriver (both flat - head and Phillips), a multimeter to test the electrical connections, and some lubricant to reassemble the starter smoothly. Having these tools ready will make the process go a lot more smoothly.

Step 1: Disconnect the Battery

Safety first! Before you start working on the starter, you need to disconnect the battery. This will prevent any electrical shocks or short - circuits while you're working. Locate the negative terminal of the battery and use a wrench to loosen the nut. Once the nut is loose, carefully remove the negative cable from the terminal.

Step 2: Remove the Starter

The next step is to remove the starter from the engine. The starter is usually located near the bottom of the engine, close to the transmission. Use your socket set to remove the bolts that hold the starter in place. There are usually two or three bolts. Once the bolts are removed, carefully pull the starter away from the engine. Be careful not to damage any of the wires or connections.

Step 3: Disassemble the Starter

Now that you have the starter out, it's time to disassemble it. Start by removing the end - cover of the starter. You can use a screwdriver to remove the screws that hold the cover in place. Once the cover is off, you'll be able to see the inside of the starter, including the field coils.

Step 4: Identify the Field Coils

The field coils are usually located around the outside of the starter's armature. They are made of copper wire wound around a core. You'll need to identify which coils need to be replaced. If you notice any signs of damage, such as burned or frayed wires, those are the coils you'll want to replace.

17302N 6bd1 starter

Step 5: Remove the Old Field Coils

To remove the old field coils, you'll need to carefully disconnect the wires that are connected to them. Use your screwdriver to loosen the terminal screws and gently pull the wires off. Once the wires are disconnected, you can use a wrench to remove the bolts or clips that hold the coils in place. Then, carefully lift the old coils out of the starter.

Step 6: Install the New Field Coils

Now it's time to install the new field coils. First, make sure the new coils are the correct size and type for your Yanmar 4JH starter. Place the new coils in the same position where the old ones were. Reconnect the wires to the coils, making sure they are tightly connected. Use your screwdriver to tighten the terminal screws. Then, use a wrench to secure the coils in place with the bolts or clips.

Step 7: Reassemble the Starter

Once the new field coils are installed, it's time to reassemble the starter. Put the end - cover back on and use your screwdriver to tighten the screws. Make sure the cover is properly aligned and there are no gaps.

Step 8: Test the Starter

Before you reinstall the starter in the engine, it's a good idea to test it. Reconnect the battery and use a multimeter to check the electrical connections. Make sure there are no short - circuits or loose connections. You can also try cranking the starter to see if it works properly.

Step 9: Reinstall the Starter

If the starter passes the test, it's time to reinstall it in the engine. Carefully place the starter back in its original position and use your socket set to tighten the bolts. Then, reconnect the battery by attaching the negative cable to the terminal and tightening the nut.

Additional Resources

If you're looking for reference numbers for other types of starters, here are some useful links:

Contact for Procurement

If you're in the market for Yanmar 4JH starters or replacement field coils, we're here to help. Whether you're a mechanic looking for quality parts or a boat owner needing to keep your engine in top shape, we've got you covered. Reach out to us to start a procurement discussion and get the best deals on the parts you need.

References

Yanmar 4JH Starter Manual
General Automotive Starter Repair Guides