Spark Plug; Ignition - Honda CR250R 2004 Owner's Manual

4. SERVICE AND MAINTENANCE

SPARK PLUG

Standard:
(NGK) BR8EG, (DENSO) W24ESR-V
Optional:
(NGK) BR8EV, (DENSO) W24ESR-G
If replacing with any other brand of spark plug, be
certain to select the correct reach and heat range.
Before removing the spark plug, clean the spark plug
area thoroughly to prevent dirt from entering the cylin-
der.
CAUTION:
•
The use of a spark plug of the incorrect reach or
heat range can cause engine damage. The use of a
non-resistor spark plug may cause ignition prob-
lems.
1. Measure spark plug gap with a feeler gauge, and
adjust by carefully bending the side electrode.
The recommended spark plug gap is:
0.020 — 0.024 in (0.5 — 0.6 mm).
2. Check the electrode for wear or deposits, the gasket
for damage, and the insulator for cracks.
(1) PLUG GAP (2) SIDE ELECTRODE
(3) SEALING GASKET
3. 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.
22
NOTE:
•
If you're using a new plug, ride for at least ten
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 47). Check the fuel/oil mixture, carburetor and
fuel system, and ignition timing.
4. Install the spark plug by hand until finger tight, then
tighten with a spark plug wrench until the sealing
gasket is compressed (1/2 turn to compress a new
spark plug gasket, 1/8—1/4 turn to compress a spark
plug with a used gasket).
(1) SPARK PLUG

IGNITION

A CDI (Capacitive Discharge lgnition) system is used on
this motorcycle; consequently, routine ignition timing
adjustment is unnecessary. If you want to check the
ignition timing, refer to the Honda Service Manual.