Page 242 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

Hot Spark Plug
In this type of spark plug, the length of the insulator is longer, due to which the central electrode remains hot
enough for a longer period, due to which carbon does not accumulate quickly around the electrode. If for some
reason the spark plug becomes hotter than necessary, it starts wearing out or its electrodes start burning quickly.
Apart from this, there is a possibility of spark not being generated because due to the gap being too wide, spark
jump is not possible.

Spark Plug Range
Spark plugs have three types of access to the cylinder or cylinder head, which are shown in the figure (a), (b) and
(c) below:
Using long range spark plugs causes the plugs to overheat. There is a possibility of damage to the piston due to
these. The outer part of this type of plug acts as a hot spot. There may also be difficulty in opening them, because
more carbon gets accumulated on them. Short reach of the spark plug can quickly lead to misfire in the engine,

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CITS : Automotive - Mechanic Diesel - Lesson 71 - 75