ignition YAMAHA TTR90 2003 User Guide

6 - 3
–+ELEC

IGNITION SYSTEM
EC622001
SPARK GAP TEST
1. Disconnect the spark plug cap from spark
plug.
2. Connect the dynamic spark tester
1
(ignition checker
2
) as shown.

Spark plug cap
3


Spark plug
4

Å
For USA and CDN
ı
Except for USA and CDN
3. Kick the kick starter.
4. Check the ignition spark gap.
5. Start engine, and increase spark gap until
misfire occurs. (for USA and CDN only)
Minimum spark gap:
6.0 mm (0.24 in)
Å
ı

EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:

Couplers and leads connection
Rust/dust/looseness/short-circuit
→

Repair or replace.
MAIN SWITCH INSPECTION
1. Inspect:

Main switch continuity
Check for continuity as follows:
Incorrect continuity
→
Replace.
Tester (+)
→
Red lead
1

Tester (–)
→
Brown lead
2
Continuous
Tester (+)
→

Black/White lead
3
Tester (–)
→
Black lead
4
Continuous
R
1
Br
2
B/W
3B
4Tester selec-
tor position
ON
Ω × 1
OFF
B/W
BrR
B
1
3
2
4

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–+ELECIGNITION SYSTEM
“ENGINE STOP” SWITCH INSPECTION
1. Inspect:
“ENGINE STOP” switch continuity
No continuous while being pushed → Replace.
Continuous while being free → Replace. Tester (+) lead → Black lead 1
Tester (–) lead → Black lead 2
B
1B
2Tester selec-
tor position
PUSH IN
Ω × 1
FREE
B B
1
2
EC626002
IGNITION COIL INSPECTION
1. Inspect:
Primary coil resistance
Out of specification → Replace.
2. Inspect:
Secondary coil resistance
Out of specification → Replace.
NOTE:
When inspecting the secondary coil resis-
tance, remove the spark plug cap.Tester (+) lead → Orange lead 1
Tester (–) lead → Black lead 2
Primary coil
resistanceTester selector
position
0.18 ~ 0.28 Ω at
20 ˚C (68 ˚F)Ω × 1
Tester (+) lead → Spark plug lead 1
Tester (–) lead → Orange lead 2
Secondary coil
resistanceTester selector
position
6.3 ~ 9.5 kΩ at
20 ˚C (68 ˚F)kΩ × 1

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–+ELECIGNITION SYSTEM
CDI MAGNETO INSPECTION
1. Inspect:
Pickup coil resistance
Out of specification → Replace.
Tester (+) lead → Red lead 1
Tester (–) lead → White lead 2
Pickup coil
resistanceTester selector
position
248 ~ 372 Ω at
20 ˚C (68 ˚F)Ω × 100
2. Inspect:
Source coil resistance
Out of specification → Replace.
Tester (+) lead → Brown lead 1
Tester (–) lead → Green lead 2
Source coil
resistanceTester selector
position
688 ~ 1,032 Ω
at 20 ˚C (68 ˚F)Ω × 100