Spark Plug - Honda CRF450R 2009 Owner's Manual & Competition Handbook

Refer to Safety Precautions on page 23.
Spark Plug Recommendation
The recommended standard spark plug is
satisfactory for most racing conditions.
Standard SILMAR9A
Optional SILMAR10A
Use only the recommended type of spark plugs in
the recommended heat range.
NOTICE
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 spark plug that have an
iridium tip in the center electrode and a platinum
tip in the side 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.
Spark Plug Inspection & Replacement
1. Remove the seat and hang the fuel tank to the
left of the frame (pages 33, 34).
2. Disconnect the spark plug cap (1).
3. Clean any dirt from around the spark plug base.
4. Remove the spark plug (2).
– 9S (NGK)
(1)
– 9S (NGK)
(1) spark plug cap
5. Check the electrodes 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:
0.031 – 0.035 in (0.8 – 0.9 mm)
(4)
(3) sealing gasket
(4) spark plug gap
7. To obtain accurate spark plug readings,
If you're using a new plug, ride for at least 10
minutes before taking a plug reading; a brand-new
plug will not 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 130).
Check the PGM-FI system and ignition timing.
8. With the sealing gasket attached, thread the
9. Tighten the spark plug.
(2)

(2) spark plug

NOTICE
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
(3)
be damaged.
10. Connect the spark plug cap. Take care to
11. Install the fuel tank and seat (pages 33, 35).
Spark Plug
accelerate up to speed on a straightaway.
Press and hold 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.
spark plug in by hand to prevent cross-
threading.
• If the old plug is good:
1/12 turn after it seats.
• If installing a new plug, tighten it twice to
prevent loosening:
a) First, tighten the plug:
NGK: 1/4 turn after it seats.
b) Then loosen the plug.
c) Next, tighten the plug again:
1/12 turn after it seats.
avoid pinching any cables or wires.
Servicing Your Honda
63