Testing Spark; Checking Spark Plug - Bosch PB-650 Service Manual

14

3-2 Testing spark

5K124
(A)

3-3 Checking spark plug

3K069
IGNITION SYSTEM
5K123
(C)
(B)
(A)
WARNING
Do not touch the spark plug while perform-
ing the test to avoid receiving electric shock.
WARNING
Do not check the spark in an area where gaso-
line is spilled or flammable gases may exist.
1. Disconnect the spark plug cap.
2. Connect the spark tester 897800-79931 (A).
3. Screw in adjuster (B) until the tips contact to-
gether and turn back four turns to set the spark tester
gap (C) to 4 mm (0.16 in).
4. Turn the ignition switch to RUN position.
5. Pull the starter grip several times.
6. If the spark is blue, white and steady by the tester
gap, the ignition system is considered good. Go to
"3-3 Checking spark plug".
7. If no spark exists or spark is red, yellow or inter-
mittent, continue with further tests according to "3-1
Troubleshooting guide".
1. Remove the spark plug, check for fouling and
worn, and rounded center electrode.
2. Clean the plug electrodes and insulator of
carbon deposits, or replace with a new plug.
3. Set the spark plug gap to 0.6 to 0.7 mm (0.024
to 0.028 in) by bending the outer electrode.
4. If the engine does not start after cranking sev-
eral times, check if the spark plug is wet or dry. If it
is excessively dry or wet, check the fuel system.
PB-650
PB-750
DANGER
DANGER