Spark plugs generate an electric spark to ignite the mixture of fuel and air within an engine. If your ZX-14 feels like it is working harder to accelerate, your spark plugs may need to be replaced. In fact, Kawasaki recommends replacing them every 7,500 miles to maintain optimal performance. The spark plugs are hidden under the ZX-14's fairings, which must be removed. On average, the entire job should take a minimum of 2 hours to complete.
Mount your ZX-14 on a service stand or lift to give you access to the motorcycle's fairings and engine.
Remove the plastic rivet from the lower fairing's chin, positioned just behind the front wheel. Pry the rivet's core out with a small flat screwdriver, then pull the rivet out of the fairing.
Unscrew the lower fairing's mounting bolts with a 4mm Allen wrench, then pull the fairing apart into two separate panels. Slip the tabs on the tops of the panels out from the slots at the base of the middle fairing panels, then set the lower fairing panels aside.
Unscrew the mounting bolts from both fairing covers -- the gill-like panels between the fuel tank and the middle fairings -- with a 4mm Allen wrench. Grasp the covers with both hands and pull them out of the mounting grommets attached to the motorcycle's frame.
Unscrew the bolts from the inner covers -- placed between the middle and upper fairings on either side of the handlebars -- with a 4mm Allen wrench. Lift the rear of the covers up slightly, then pull them backwards until they release from the hooks on the upper and middle fairings.
Unscrew the single bolt from the top of the fuel tank, placed below the handlebars, with a 5mm Allen wrench. Grasp the sides of the fuel tank's plastic cover, which extends from the front of the tank to its sides in a V-shape, then gently spread the cover apart until its tabs are freed from the rubber grommets attached to the tank and the middle fairings. Lift the fuel tank cover away from the motorcycle.
Unscrew both middle fairing panels' mounting bolts with a 5mm Allen wrench, then remove the plastic rivets attaching the middle fairing panels to the bottom of the upper fairing with a small flat screwdriver. Pull the middle fairing panels from the motorcycle, then reach around the panels and unplug the front indicators. Set the middle fairing panels aside.
Unplug the ignition stick coils from the motorcycle's wiring harness. The stick coils extend out from the top of the engine, two on either side of the frame's backbone. Pull the stick coils straight up and off of the spark plugs, then set them aside in the order they were removed. Unscrew the spark plugs with the 16mm spark plug wrench included in the ZX-14's tool kit. Be careful to hold the wrench completely vertical when unscrewing the spark plugs to avoid snapping the spark plugs' ceramic insulators.
Hold the spark plugs with their electrodes, the portion that fits into the motor, facing upward. Examine the condition of each spark plug's electrode for uneven wear, cracks or rounding of the electrode's tip. Ideally, the electrode's tip will have a squared-off profile with a flat top. Replace the spark plug with a new NGK CR9EIX spark plug, if the electrode is damaged in any way.
Look at the overall condition of the spark plugs. A normally functioning ZX-14 will turn the tips of the spark plugs a light tan colour. If the spark plugs are oily or are burnt white, your ZX-14 may be experiencing internal engine or fuel problems that will require further troubleshooting by your local Kawasaki dealer. If the spark plugs appear to be in good condition, screw the spark plugs into the engine by hand, then tighten them to 116 inch-pounds with a torque wrench.
Press the ignition stick coils over the tops of the spark plugs, aligning the electrical plug on the top of the stick coil with the arrows imprinted onto the top of the engine. Reconnect the stick coils to the motorcycle's wiring harness.
Reinstall the fairings and fuel tank cover onto your ZX-14, following the reverse order of removal.