Kohler COMMAND CH18-745 Service Manual page 118

Electrical System and Components
This section covers the operation, service and repair of
the electrical system components. Systems and
components covered in this section are:
• Spark Plugs
• Battery and Charging System
• Electronic CD Ignition System (including SMART-
SPARK on applicable models)
™
• Electric Starter
Spark Plugs
Engine misfire or starting problems are often caused
by a spark plug that has improper gap or is in poor
condition.
The engine is equipped with the following spark plugs:
Type: The standard spark plug is a Champion
RC12YC (Kohler Part No. 12 132 02-S). A
high-performance spark plug, Champion
Platinum 3071 (used on Pro Series engines,
Kohler Part No. 25 132 12-S) is also available.
Equivalent alternate brand plugs can also be
used.
Gap: 0.76 mm (0.030 in.)
Thread Size: 14 mm
Reach: 19.1 mm (3/4 in.)
Hex. Size: 15.9 mm (5/8 in.)
Spark Plug Service
Every 200 hours of operation, remove each spark
plug. Check its condition and either reset the gap or
replace with a new plug as necessary. To service the
plugs, perform the following steps:
1. Before removing each spark plug, clean the area
around the base of the plug to keep dirt and
debris out of the engine.
2. Remove the plug and check its condition. See
"Inspection" following this procedure. Replace the
plug if necessary.
Electrical System and Components
Section 8
NOTE: Do not clean spark plug in a machine
3. Check the gap using a wire feeler gauge. Adjust
the gap to 0.76 mm (0.030 in.) by carefully
bending the ground electrode. See Figure 8-1.
Wire Gauge
Spark Plug
®
®
Ground
Electrode
Figure 8-1. Servicing Spark Plug.
4. Reinstall the spark plug into the cylinder head and
torque to 24.4-29.8 N·m (18-22 ft. lb.).
Inspection
Inspect each spark plug as it is removed from the
cylinder head. The deposits on the tip are an indication
of the general condition of the piston rings, valves, and
carburetor.
Normal and fouled plugs are shown in the following
photos:
using abrasive grit. Some grit could
remain in the spark plug and enter the
engine causing extensive wear and
damage.
0.76 mm (0.030 in.) Gap
Section 8
CH18-745
8
8.1