stop start YAMAHA YZ125LC 2005 User Guide

4-8
ENGCARBURETOR AND REED VALVE
EC468000
CARBURETOR DISASSEMBLY
Extent of removal Order Part name Q’ty Remarks
CARBURETOR DISASSEMBLY
1Mixing chamber top 1
2Throttle valve 1 Refer to “REMOVAL POINTS”.
3Needle holder 1
4Jet needle 1
5Float chamber 1
6Needle jet cover 1
7Float pin 1
8Float 1
9Valve seat 1
0Main jet 1
qMain jet holder 1
wPilot jet 1
eStarter plunger 1
rThrottle stop screw 1
tPilot air screw 1
Extent of removal:1Carburetor disassembly
1
4 Nm (0.4 m•kg, 2.9 ft•lb)
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4-13
ENGCARBURETOR AND REED VALVE
2. Install:
9Reed valve assembly 1
9Reed valve spacer 2
3. Install:
9Carburetor joint 1
9Bolt (carburetor joint) 2
EC4652C2
Carburetor
1. Install:
9Throttle stop screw 1
9Locknut 2
9Pilot air screw 3
Pilot air screw:
2-1/4 turns out
Note the following installation points:
9Screw in the pilot air screw until it is lightly
seated.
9Back out it by the specified number of turns.
10 Nm (1.0 m•kg, 7.2 ft•lb)
2. Install:
9Starter plunger 1
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6-3
ELECIGNITION SYSTEM
EC622001
SPARK GAP TEST
1. Disconnect the spark plug cap from spark
plug.
2. Connect the dynamic spark tester 1(igni-
tion checker 2) as shown.
9Spark plug cap 3
9Spark plug 4
AFor USA and CDN
BExcept 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)
EC624000
COUPLERS AND LEADS CONNECTION
INSPECTION
1. Check:
9Couplers and leads connection
Rust/ Dust/ Looseness/Short-circuit 
Repair or replace.
EC625002
“ENGINE STOP” BUTTON INSPECTION
1. Inspect:
9“ENGINE STOP” button conduct
Not continuous while being pushed Replace.
Continuous while being freed Replace.
Minimum spark gap:
6.0 mm (0.24 in)
Tester (+) leadBlack/White lead 1
Tester (–) lead
Black lead 2
B/W B
12
PUSH IN
FREE
Tester selector
position
Ω× 1
å
∫
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