Spark Plug - Suzuki RM85 Owner's Service Manual

2-4 PERIODIC MAINTENANCE

SPARK PLUG

• Inspect the spark plug condition, electrode color, carbon
deposits, spark plug gap, and washer damage, after removing
the spark plug.
NOTE:
Remove the dirt around the spark plug before removing the
spark plug to prevent dirt from entering the combustion cham-
ber.
• Inspect the porcelain tip color.
Porcelain tip color
White (overheated)
Black (fouled)
• Check the spark plug gap with a thickness gauge.
 Spark plug gap: 0.7 – 0.8 mm (0.028 – 0.031 in)
 Standard Spark plug
NGK
Changing the spark plug heat range improperly can
damage the engine.
Select the spark plug heat range only after adjusting
the ignition timing, carburetor setting and oil/gasoline
mixture.
• Tighten the spark plug with specified tightening torque after
tightening the spark plug temporarily with fingers.
 Spark plug: 28 N·m (2.8 kgf-m, 20.5 lb-ft)
Cause
• Hot type spark plug
• Advanced ignition timing
• Lean air/fuel mixture
• Deteriorated fuel
• Cold type spark plug
• Retarded ignition timing
• Rich air/fuel mixture
• Rich oil/gasoline mixture
BR10ES
CAUTION
0.7 – 0.8 mm
(0.028 – 0.031 in)