Honda 2007 CRF250R Owner'S Manual Download Page 60

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Servicing Your Honda

Refer to Safety Precautions on page 19.

Spark Plug Recommendation

The recommended standard spark plug is
satisfactory for most racing conditions.

Use only the recommended type of spark plugs in
the recommended heat range.

Using a spark plug with an improper heat range
or incorrect reach can cause engine damage.
Using a non-resistor spark plug may cause
ignition problems.

This motorcycle uses a spark plug that has an
iridium tip in the center electrode and a platinum
tip in the side the electrode.
Be sure to observe the following when servicing
the spark plug.
•

Do not clean the spark plug. If an electrode is
contaminated with accumulated objects or
dirt, replace the spark plug with a new one.

•

To check the spark plug gap, use only a
“wire-type feeler gauge.” To prevent
damaging the iridium tip of the center
electrode and platinum tip of the side
electrode, never use a “leaf-type feeler
gauge.’’

•

Do not adjust the spark plug gap. If the gap is
out of specification, replace the spark plug
with a new one.

NOTICE

Spark Plug

Spark Plug Replacement & Inspection

1. Remove the seat and fuel tank (pages 29,30).
2. Disconnect the direct ignition coil (1).
3. Clean any dirt from around the spark plug bases.
4. Remove the spark plug (2).

7. To obtain accurate spark plug readings,

accelerate up to speed on a straightaway. Push
the engine stop button and disengage the
clutch by pulling the lever in.
Coast to a stop, then remove and inspect the spark
plug. The porcelain insulator around the center
electrode should appear tan or medium gray.

If you're using a new plug, ride for at least 10
minutes before taking a plug reading; a brand-new
plug will not appers color initially.

If the electrodes appear burnt, or the insulator is
white or light gray (lean) or the electrodes and
insulator are black or fouled (rich), there is a
problem elsewhere (page 128).
Check the carburetor, fuel system and ignition
timing.

8. With the sealing gasket attached. Thread the

spark plug in by hand to prevent cross-
threading.

9. Tighten the spark plug:

• If the old plug is good:

1/8 turn after it seats.

• If installing a new plug, tighten it twice to

prevent loosening:
a) First, tighten the plug:

NGK: 1/2 turn after it seats.

b) Then loosen the plug.
c) Next, tighten the plug again:

1/8 turn after it seats.

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.

NOTICE

(1) direct ignition coil
(2) spark plug

5. Check the electrode for wear or deposits, the

sealing gasket (3) for damage, and the
insulator for cracks. Replace if you detect
them.

6. Check the spark plug gap (4), using a wire-type

feeler gauge. If the gap is out of specifications,
replace the plug with a new one.
The recommended spark plug gap is:

0.024 – 0.028 in (0.6 – 0.7 mm)

(3) sealing gasket
(4) spark plug gap

(1)

(2)

(3)

(4)