Learn with CMS - How to Replace a Sparkplug in Your Honda CB750

If you own a Honda cb750, you know how important it is to keep your engine running smoothly and efficiently. One of the key components that affects your engine performance is the sparkplug. The sparkplug is responsible for igniting the fuel-air mixture in the combustion chamber, creating the power that drives your bike. However, over time, the sparkplug can wear out, get dirty, or even break, causing problems such as poor acceleration, misfiring, or hard starting. That's why it's recommended to replace your sparkplug every 10,000 miles or so, depending on your riding conditions and habits.

Replacing a sparkplug in your Honda cb750 is not a difficult task, but it does require some basic tools and skills. Here are the steps you need to follow to do it yourself:

1. First, you need to locate the sparkplug on your bike. The Honda cb750 has four sparkplugs, one for each cylinder. They are located on the top of the engine, under the fuel tank. You may need to remove the fuel tank to access them. To do that, turn off the fuel valve, disconnect the fuel hose from the carburetor, and unscrew the bolts that hold the tank in place. Then lift the tank off and set it aside.
2. Next, you need to remove the sparkplug wires from the sparkplugs. The wires are color-coded and numbered to match the cylinders. To avoid confusion, you should remove and replace one sparkplug at a time. To remove a wire, grasp it by the rubber boot and pull it off gently. Do not pull on the wire itself, as you may damage it.
3. Now you can remove the old sparkplug from the cylinder. You will need a sparkplug wrench or socket that fits your sparkplug size. Insert the wrench or socket over the sparkplug and turn it counterclockwise to loosen it. Then pull it out and inspect it for signs of wear or damage. A good sparkplug should have a light brown or gray color on the electrode and insulator. If you see any black deposits, cracks, or erosion, it means your sparkplug is bad and needs to be replaced.
4. Before you install the new sparkplug, you need to check its gap. The gap is the distance between the electrode and the metal hook at the end of the sparkplug. The gap affects how well the sparkplug ignites the fuel-air mixture in the cylinder. If the gap is too wide or too narrow, it can cause poor engine performance or damage. The correct gap for your Honda cb750 is 0.6-0.7 mm (0.024-0.028 in). You can measure the gap with a feeler gauge or a coin gauge and adjust it by bending the metal hook slightly with a pair of pliers.
5. Once you have checked and adjusted the gap, you can install the new sparkplug in the cylinder. Apply a thin layer of anti-seize compound on the threads of the sparkplug to prevent corrosion and make future removal easier. Then insert the sparkplug into the cylinder and tighten it with your wrench or socket until it is snug. Do not over-tighten it, as you may damage the threads or crack the insulator.
6. Finally, you need to reconnect the sparkplug wire to the sparkplug. Make sure you match the color and number of the wire to the cylinder. Push the rubber boot over the sparkplug until it clicks into place.
7. Repeat steps 2-6 for each of the remaining cylinders.
8. After you have replaced all four sparkplugs, you can reinstall the fuel tank on your bike. Reconnect the fuel hose to the carburetor, turn on the fuel valve, and secure the tank with its bolts.
9. Start your engine and check for any leaks or noises. If everything sounds normal, you have successfully replaced your sparkplugs and improved your engine performance.

Congratulations! You have just learned how to replace a sparkplug in your Honda cb750 by yourself. This is a simple and rewarding maintenance task that can save you money and time in the long run. Remember to check your sparkplugs regularly and replace them when needed to keep your bike running smoothly and efficiently.

If you need any parts or accessories for your Honda cb750, visit CMSnl.com for a wide selection of high-quality products at competitive prices.

issued: Tuesday, April 18, 2023
updated: Tuesday, April 18, 2023

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