Spark plug – HONDA CRF50F User Manual

Page 88

Advertising
background image

0.024

0.028 in (0.60

0.70 mm)

80

Spark Plug

Servicing Your Honda

An improperly tightened spark plug can
damage the engine. If a plug is too loose, a
piston may be damaged. If a plug is too tight,
the threads may be damaged.

Tighten the spark plug:

Disconnect the spark plug cap.

Clean any dirt from around the spark plug
base.

Remove the spark plug with a plug wrench.
Inspect the spark plug electrodes for wear.
The center electrode ( ) should have square
edges. The side electrode ( ) should not be
eroded. The insulator should not be cracked
or chipped.
Check the spark plug gap ( ), using a wire-
type feeler gauge. If adjustment is necessary,
bend the side electrode carefully. The gap
should be:

Make sure the plug washer is in good
condition.
If you have to install a new plug, first check
the gap.
With the plug washer attached, thread the
spark plug in by hand (to prevent cross-
threading).

If the old plug is good:
1/8 turn after it seats.
If installing a new plug, tighten it twice to
prevent loosening:

First, tighten the plug:
NGK:

turn after it seats.

DENSO:

turn after it seats.

Then loosen the plug.
Next, tighten the plug again:
1/8 turn after it seats.

Reinstall the spark plug cap. Take care to
avoid pinching any cables or wires.

2.
3.
4.

5.

6.

7.

3

1

1.

2

8.

a)

c)

b)

1

3/4

Advertising