The spark plugs are easy to spot on the left side of the motorcycle.
The procedure for removing the spark plugs is the same for both the front and back cylinder, and either spark plug can be replaced first. This guide will show how to remove and install the spark plug in the rear cylinder.
Always inspect your new spark plugs before installing. Check the gap on your replacement spark plugs with a feeler gauge. It should be set to .040 inches (1.016mm).
If they are not pre-installed, make sure that the crush washer and terminal nut are installed.
Using your fingers, install the new spark plug into the socket, and hand tighten until firm.
Using a torque wrench, tighten the spark plug to the proper specification.
When installing spark plugs, proper torque can be important. To loose and they could rattle out or leak; too tight and you can strip your cylinder head. The correct torque for this plug is between 90 and 120 inch lbs.
Just for information, particularly in the UK, you may be able to purchase sparking plugs cheaper at a Chandlers, as there are quite a few 4-stroke outboard engines use these plugs.
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