Kohler K9J Service Manual page 74

NEGATIVE
-_/TERMINAL
TO CONDENSER
&
POINTS
MOUNTING
BRACKET
Figure 8-4. Typical Battery Ignition Coil.
Battery Ignition Service - 1 0 - 16 HP
Single Cylinder Models
Ignition problems and poor performance on these
models are often the result of using an incorrect
ignition coil, spark plug, or plug gap setting. When
replacing an ignition coil always use the genuine
Kohler replacement. Use of the correct spark plug
and gap setting is also important. The specified
plug is a Champion H10/RH10, or equivalent,
gapped at .035" (.9mm). Failure to follow these
recommendations will result in erratic high speed
ignition misfire or cutting-out under load.
AC WINDING
(ON STATOR)
DIODE 2
DIODE l
Breakerless Ignition System Operation
The breakerless ignition system operates on the
same general principle as the magneto system but
does not use breaker points and conventional igni-
tion condenser to time the spark. A trigger module
containing solid state electronics performs the
same function as the breaker points. Refer to Fig-
ure 8-5.
The breakerless system consists of four major
components:
• Ignition winding on alternator stator
• Trigger module
• Ignition coil assembly
• Flywheel-mounted trigger
The ignition winding is separate from the other
windings on the alternator stator. It functions like
the magneto winding. The trigger module contains
three diodes, a resistor, a sensing coil and mag-
net and an SCR, a sort of electronic switch. The
ignition coil assembly includes a capacitor and a
pulse transformer that serves the same purpose
as the ignition coil in other systems. The flywheel
has a projection that triggers ignition. Refer to Fig-
ure 8-6.
In some applications a 22 ohm, 1/2 watt resistor
has been placed between the key switch and the
ignition coil. This has been added to prevent cur-
rent feedback through a dirty or wet switch. This
feedback, if not held in check by a resistor, can
damage the trigger unit.
CAPACITOR
Figure 8-5. Schematic Of Typical Breakerless Ignition System.
8.4