How to Change Spark Plugs in an Bikes

by Contributing Writer; Updated June 12, 2017

Regular replacement of the spark plugs will improve the performance of your Kawasaki bike motorcycle, ensuring the consistent spark quality required to create combustion within the motor. Earlier Kawasaki bike models made spark plug replacement an easy task, placing the plugs in easily-reached areas. Newer models, however, place the spark plugs beneath fuel tanks and fairings. The job can still be accomplished with a few hand tools, and requires a bit more work and determination on harder-to-access models. If you have access to a Kawasaki bike service manual for your specific bike, you may want to familiarize yourself with the process.

Under The Hood:

 How to Change Spark Plugs in an 1100 Honda Shadow Ace

Park your 1100 Honda Shadow Ace on a level surface in a well lit area. Wait for the engine to completely cool before proceeding.

Remove the rubber wires from the tops of each spark plug. Connect the spark plug socket to the ratchet and remove the spark plugs from the engine.

Place the edge of the spark plug gapper between the metal arm and the pin in the center of a new spark plug. Turn the gapper until the number .036 is in the center of the metal arm. Repeat for all three of the new spark plugs.

Insert the new NGK motorcycle spark plugs into the spark plug holes on the engine. Tighten the new spark plugs using the ratchet and spark plug socket. Replace the rubber wires onto the spark plugs.

Items you will need

  • Ratchet

  • Spark plug socket

  • NGK motorcycle spark plugs (4)

  • Spark plug gapping tool

 How to Replace Spark Plugs on a Gold Wing GL1200

Remove the side plates that conceal the spark plug on the right and left sides of the engine, using the ratchet set. Pull the side plates off the engine and remove the spark plug wires from the spark plugs.

Connect the spark plug socket to the ratchet and remove the spark plugs from the top of the engine. Place the thin edge of the spark plug gapper between the arm and the pin of a new spark plug, so that the numbers on the front are facing you.

Turn the gapper until it gives a reading of .28 in. Insert all of the new spark plugs into the engine after you have gapped all of them to the above specification. Tighten the new plug s to 12 foot-pounds, using the torque wrench, and replace the side plates on the engine.

Items you will need

  • Ratchet set

  • Spark plug socket

  • Spark plug gapper

  • New spark plugs

 How to Replace Spark Plugs on My Kawasaki

Ninja Series (ZX and EX models)

Locate your spark plugs before beginning. Accessing the spark plugs can vary greatly depending on the model of motorcycle. The Ninja series bikes place the spark plugs near the top of the motor, hidden beneath the fuel tank and air box.

Remove the seat and fuel tank. Locate the bolts that secure the fuel tank to the frame and remove them with a socket wrench. Lift the fuel tank upwards and disconnect the fuel lines. Pull the entire tank away from the motorcycle and set it aside.

Unscrew the air box lid with a screwdriver and remove. Remove the air filter and locate the bolts that secure the air box to the motor. Unscrew the bolts with a screwdriver and pull the air box off of the motor. Take note of the locations of any wiring or hoses that may be attached to the air box before disconnecting them.

Pull the spark plug wire off of the first spark plug and clear the plug cavity with compressed air to remove dirt or debris that may been trapped. Remove the spark plug with a spark-plug socket. If needed, use a socket extension to reach the spark plug in the cavity.

Insert a new spark plug into the cavity and carefully tighten with a spark plug socket. Slide the spark plug wire onto the end of the spark plug and press down until the wire clicks into place.

Repeat as necessary for any remaining spark plugs. Reinstall the air box and reconnect any hoses or wiring removed earlier. Insert the air filter into the air box and seal the lid by tightening its bolts with a screwdriver.

Reinstall the fuel tank, reconnecting the fuel lines and tightening the mounting bolts with a socket wrench. Replace the seat.

Vulcan Series (VN Models)

Locate the spark plugs on both cylinders of the motor and clear the cavities with compressed air to remove trapped dirt or debris.

Pull the spark plug wire off of the first spark plug. Remove the spark plug with a spark-plug socket. If needed, use a socket extension to reach the spark plug in the cavity.

Insert a new spark plug into the cavity and carefully tighten with a spark-plug socket. Slide the spark plug wire onto the end of the spark plug and press down until the wire clicks into place.

Repeat as necessary for any remaining spark plugs.

Items you will need

  • Socket wrench

  • Socket set

  • Screwdrivers

  • Air compressor

  • Spark plug socket

  • Socket extensions

  • Spark plugs

 How to Replace the Spark Plugs on a Kawasaki Ninja

Remove the seat by pressing the release tab on the seat assembly with your hand.

Remove the two bolts securing the gas tank to the frame, located underneath the front of the seat toward the handlebars.

Remove each bolt on the side of the gas tank that attaches it to the fairing, using a ratchet and socket.

Slide the vacuum hose and fuel hose off the gas tank with pliers. Slide the tank out of the way.

Locate the two spark plug wires. Remove the spark plug wires one at a time to avoid confusion, by pulling on the spark plug wire boot. (The boot is the end of the spark plug wire that attaches to the spark plug.)

Remove the spark plug with a spark plug socket, by turning the wrench counterclockwise.

Apply a small amount of anti-seize lubricant to the threads of the replacement spark plug, and insert the plug into the spark plug well in the engine. Tighten the spark plug to 20 foot-lbs. with a torque wrench.

Apply a small amount of dielectric grease to the tip of the spark plug, and attach the boot of the spark plug wire onto the tip of the spark plug.

Repeat these steps with the opposite spark plug.

Replace the gas tank in the reverse order.

Items you will need

  • Ratchet

  • Socket set

  • Pliers

  • Spark plug socket

  • Anti-seize lubricant

  • Torque wrench

  • Dielectric grease

 How do I Change a Spark Plug on a Yamaha Road Star?

Locate the spark plugs on the engine of your Yamaha Road Star. Grasp the spark plug wires near the base of the spark plug and pull each one off one at a time.

Remove the current spark plugs with a ratchet socket set and discard them.

Install the spark plugs using your hand to turn them into place as far as you can. Use the ratchet and socket set to give each of the spark plugs a final 1/16 of a turn.

Reconnect your spark plug wires by snapping them into place at the base of the spark plugs.

Items you will need

  • Spark plugs

  • Ratchet and socket set

 How to Change Spark Plugs in a Yamaha 1100 V Star

Look on the back of the pillion pad to find the bolt that holds the seat in place on your Yamaha 1100 V Star. Remove this bolt with an Allen wrench. Grab the pad and pull it toward the back of the bike until it releases from the rider's seat bracket.

Find the two bolts that hold the rider's seat in place and remove these as well. Lift the back of the seat and pull it toward the back to release it.

Go to the fuel tank, find the bolts that hold the base of it in place against the frame and remove these bolts with a socket wrench. Place a drip pan under the area you are working on. Lift the fuel tank a bit until you can reach around to disconnect the fuel lines. Some fuel may leak into the drip pan.

Raise the fuel tank and pull it back until it comes off the rubber damper. Disconnect the wiring harness on the back of the fuel tank and put the tank to the side.

Find the black wire that was under the fuel tank that runs from the ignition coils. This will lead you to the spark plug area.

Grab the wire cap and pull it off of the spark plug. Place a spark plug socket wrench with an extender attached on to the spark plug and turn it counterclockwise. Put the old spark plug to the side.

Place a new spark plug in the spark plug hole and tighten it in place in a clockwise direction until snug against the cylinder. Do not over-tighten. Put the wire cap back on, and then perform the procedure again to replace the second spark plug.

Replace the fuel tank wiring harness, fuel tank, and seats when you are finished replacing the spark plugs. Safely and responsibly discard the old spark plugs and any fuel that leaked out in the fuel-tank removal process.

Items you will need

  • Allen wrench set

  • Drip pan

  • Socket wrench set

  • Spark plug socket

  • Socket extension bar

  • 2 spark plugs, part number NGK #BPR7ES

 How to Replace the Spark Plugs on a Yamaha R6

Remove the rider's seat, using an Allen head socket to unscrew the two mounting bolts at the rear of the seat.

Unbolt the fuel tank. Use an Allen head socket to remove the pair of bolts securing the front of the fuel tank and the single bolt at the base of the fuel tank. Lift the tank upwards and disconnect the two wiring harnesses from the tank. Disconnect the fuel lines, taking note of their location and arrangement. Set the tank aside.

Remove the air box cover by removing the bolt closest to the handlebars. Lift the cover away and disconnect the hose clamps. Use a Phillips head screwdriver to remove the pair of screws that secure each intake duct to the air box and pull off the hose clamps. Pull the air box out of the frame and remove the head shield hidden beneath the air box.

Disconnect and remove the ignition coils one at a time. Using a spark plug socket, unscrew and remove the spark plugs from the cylinder. Coat the threads of the new spark plugs with anti-seize compound and carefully screw them into the cylinder. Do not over-tighten the spark plugs. Reinstall the ignition coils and connect them to their wiring harnesses.

Reinstall the heat shield and lower air box. Reconnect the air ducts and hose clamps before installing the air box cover. Reconnect the fuel lines and harnesses to the fuel tank. Remount the rider's seat.

Items you will need

  • Allen sockets

  • Socket wrench

  • 10mm wrench

  • Phillips head screwdriver

  • Spark plug socket

  • Anti-seize compound

  • Spark plugs, CR9EK (4)