Spark Plug - Dinli DL-801 Service Manual

APPENDIX

Spark Plug:

The spark plug ignites the fuel and air mixture in the
combustion chamber. To do this effectively and at the proper
time, the correct spark plug must be kept clean and the gap
adjusted.
Tests have shown the plug listed in the General Information
chapter to be the best plug for general use.
Since spark plug requirements change with the ignition and
carburetion adjustments and with riding conditions, whether
or not a spark plug of the correct heat range is used should be
determined by removing and inspecting the plug.
Terminal [A]
Gasket [C]
Gap [E] (0.6 – 0.7 mm) Reach [F]
Side Electrode [G]
When a plug of the correct heat range is being used, the
electrodes will stay hot enough to keep all the carbon burned
off, but cool enough to keep from damaging the engine and
the plug itself. This temperature is about 400 ~ 800
o
1,450 F) and can be judged by noting the condition and color
of the ceramic insulator around the center electrode.
If the ceramic is clean and of a light of a light brown color, the
plug is operating at the right temperature.
A spark plug for higher operating temperatures sometimes
may be needed for severe conditions, such as continuous
high-speed riding, or towing heavy loads. Such a plug is
designed for better cooling efficiency so that it will not
overheat and thus is often called a "colder" plug. If a spark
plug with a heat range is used – that is, a "cold" plug that
cools itself too well, - the plug will stay too cool to burn off
the carbon, and the carbon will collect on the electrodes and
the ceramic insulator.
Insulator [B]
Center Electrode [D]
o
C(750 ~
【8-4】