Testing Spark; Inspecting Spark Plug - Yamabiko ECHO SRM-420ES Service Manual

SRM-420ES, SRM-420TES
T410S, B410S
T410TS, B410TS

3-2 Testing spark

B

3-3 Inspecting spark plug

3K069
IGNITION SYSTEM
a2
a1
A
B
A
1. Remove spark plug cap from spark plug.
2. Connect spark plug cap to spark tester 897800-
79931 (A), and connect spark tester lead (B) on
spark plug as shown.
3. Screw in adjuster (a1) until the needle tips con-
tact. Turn out adjuster (a1) 4 turns to set spark
tester gap (a2) to 4 mm (0.16 in).
4. Turn ignition switch to "RUN" position. Pull start-
er grip several times.
5. If spark is steady in blue or white at the tester
gap, ignition system is considered good.
6. If no spark exists or spark is intermittent in
yellow, orange, or red, continue with further inspec-
tion.
WARNING
*Do not test near spark plug hole without
spark plug installed, otherwise there is a
chance to ignite fuel mixture inside cylinder.
*Do not touch metal parts of spark tester
while performing the test to avoid receiving
electrical shock.
*Do not check spark in area where gasoline
is spilled or fl ammable gases may exist.
1. Remove spark plug to inspect for fouling,
cracked or broken insulator, cracked outer elec-
trode, or rounded center electrode. Clean or
replace spark plug as required.
2. Set spark plug gap (A) by bending outer elec-
trode (B).
Standard : 0.6 to 0.7 mm (0.024 to 0.028 in)
NOTE: Take care not to crank outer electrode
when bending.
3. If engine does not start with correct spark plug,
inspect if spark plug is wet or dry. If it is excessive-
ly wet or dry, inspect fuel system.
15 15
DANGER