9.3 Spark plug maintenance.
Recommended spark plugs: TORCH F6RTC, NGK BP7ES, BOSCH WR3C.
1. Open the big access cover for maintenance.
2. Remove the cap of spark plug (2), pulling it out.
3. With a spark plug wrench unscrew (3) and remove the spark plug (1) from
the engine (turn counterclockwise).
4. Visually check the spark plug. If the spark plug insulation is cracked or
chipped, replace it with a new one. To clean dirt on the electrode, use a
very thin wire brush.
5. Check the electrode distance with a caliper. The distance should be
between 0.7 and 0.8mm. If it does not match, adjust it carefully.
6. Carefully put back the spark plug, starting its threading manually to avoid
the damage of the thread. With the spark plug fully threaded make a final
tightening with a spark plug wrench, according to the following
recommendations:
• New spark plugs: 1/2 turn
• Used spark plugs: 1/8 to 1/ 4 turn
7. Put back the cap of the spark plug and close the big access cover.
NOTE: The spark plug must be firmly tightened. An incorrectly fitted spark
plug can heat up and even damage the engine. On the other hand, over-tightening
can damage the spark plug and damage the thread of the cylinder head.
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