Attach the spark plug to a spark plug tester, then connect the tester to the ignition wire. Start the engine and observe the ...

Let's say you've just removed an old spark plug. Does it have any life left in it? Can it be reused if it is cleaned properly? Let's take a closer look.

Hand-thread the spark plug back into the engine, being very careful not to cross the threads. Then tighten the spark plug, but don’t over-tighten it or it’ll crack.

A clogged silencer and fuel screw adjustments bring the engine to life. With a clean spark plug and proper idle speed regulation, the Honda Dio AF 27 is running smoothly again.