Troubleshooting - Shindaiwa 300 Service Manual

Basic
Most ignition failures can be traced to a single
component or connection. The goal of basic

Troubleshooting

troubleshooting is to quickly perform a "pass-
fail" diagnosis on all wiring and connections,
and to evaluate ignition components that can
be accurately tested with a minimum of
equipment.
any Shindaiwa saw. Basic ignition trouble-
shooting requires a reliable ohmmeter, an
adjustable-gap spark tester (Figure 5.4), and a
systematic approach to the problem at hand.
IMPORTANT!
The Spark Plug Remove and inspect the spark plug for proper
size, gap, and condition (refer to the accom-
panying Table). A plug with a worn, damaged,
or improperly gapped electrode will require a
higher firing voltage and will "cut out" under
load whenever its required voltage ap-
proaches the maximum voltage available from
the ignition system (Figure 5.5).
The following procedures can be used on
Most ignition troubleshooting can be
completed in five minutes or less, and can
be performed without disassembling the
saw.
ATTENTION!
Spark plug heat range and dimensions
are critical to the performance and
lifespan of any gasoline engine! Installing
a plug with a heat range higher than
specified may cause pre-ignition, and
can shorten engine life drastically! Always
verify the correct plug is installed!
Ignition Systems
Sensitive
Ohmmeter
Figure 5.4 Essential Tools
Normal
Fouled
Figure 5.5 Spark Plug Troubleshooting
Spark
Plug
(Champion
Model /NGK)
300 CJ8Y/BPM6A
300S CJ8Y/BPM6A
360 CJ6Y/BPM7A
377 CJ6Y/BPM7A
357T CJ6Y/BPM7A
488 CJ6Y/BPM7A
575 CJ6Y/BPM7A
577 CJ6Y/BPM7A
680 CJ6Y/BPM7A
695 CJ6Y/BPM7A
757 CJ6Y/BPM7A
n/a = not applicable
Shindaiwa Inc. 1995
5
Section
Adjustable-gap
Spark Tester
IGN-24
Jumper Lead
Incorrect Gap
Worn Electrode
IGN-28
Spark Exciter Pulser
Plug Coil Air Coil Air
Gap Gap Gap
(in./mm) (in.) (in.)
.024/.6 .018-.020 n/a
.024/.6 .018-.020 n/a
.024/.6 .018-.020 n/a
.024/.6 .018-.020 n/a
.024/.6 .012-.014 n/a
.024/.6 .012-.014 n/a
.024/.6 .018-.020 .018-.020
.024/.6 .018 n/a
.024/.6 .012-.014 .012"-.014
.024/.6 .018-.020 .018-.020
.024/.6 .020 n/a
49