Yamaha YZ450F(S) Owner's Service Manual page 572

Å
ı
2
IGNITION SYSTEM
SPARK GAP TEST
Å For USA and CDN
ı Except for USA and CDN
COUPLERS, LEADS AND IGNITION COIL
CONNECTION INSPECTION
EC625001
"ENGINE STOP" BUTTON INSPECTION
2 1
B B/W
1
No continuity while being pushed → Replace.
Continuity while being freed → Replace.
6 - 4
1. Disconnect the ignition coil from spark
plug.
2. Remove the ignition coil cap.
3. Connect the dynamic spark tester 1
(ignition checker 2) as shown.
Ignition coil 3
G
Spark plug 4
G
4. Kick the kick starter.
5. Check the ignition spark gap.
6. Start engine, and increase spark gap until
misfire occurs. (for USA and CDN only)
Minimum spark gap:
6.0 mm (0.24 in)
1. Check:
Couplers and leads connection
G
Rust/dust/looseness/short-circuit →
Repair or replace.
Ignition coil and spark plug as they are
G
fitted
Push in the ignition coil until it closely
contacts the spark plug hole in the cyl-
inder head cover.
1. Inspect:
"ENGINE STOP" button conduct
G
Tester (+) lead → Black/White lead 1
Tester (–) lead → Black lead 2
B/W
1
PUSH IN
FREE
– +
ELEC
Tester selec-
B
tor position
2
Ω × 1