2002 YAMAHA YZ250LC checking oil

EC0A0000
CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION............................................1-1
MACHINE IDENTIFICATION......................1-2
IMPORTANT INFORMATION.....................1-3
CHECKING OF CONNECTION..................1-6
SPECIAL TOOLS........................................1-7
CONTROL FUNCTIONS.............................1-9
FUEL AND ENGINE MIXING OIL.............1-12
STARTING AND BREAK-IN.....................1-13
TORQUE-CHECK POINTS.......................1-16
CLEANING AND STORAGE....................1-17
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS....................2-1
MAINTENANCE SPECIFICATIONS...........2-3
GENERAL TORQUE SPECIFICATIONS..2-12
DEFINITION OF UNITS............................2-12
CABLE ROUTING DIAGRAM..................2-13
CHAPTER 3
REGULAR INSPECTION
AND ADJUSTMENTS
MAINTENANCE INTERVALS.....................3-1
PRE-OPERATION INSPECTION AND
MAINTENANCE..........................................3-4
ENGINE.......................................................3-5
CHASSIS...................................................3-17
ELECTRICAL............................................3-38
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1-8
SPECIAL TOOLS
GEN
INFO
Part number Tool name / How to use IIIustration
YU-33975, 90890-01403 Ring nut wrenchYU-33975 90890-01403
This tool is used when tighten the steering ring nut
to specification.
YM-1423, 90890-01423 Damper rod holder
YM-1423 90890-01423
Use this tool to remove and install the damper rod.
YM-01442, 90890-01442 Fork seal driver
YM-01442 90890-01442
This tool is used when install the fork oil seal.
YU-3112-C, 90890-03112 Yamaha pocket tester
YM-3112-C 90890-03112
Use this tool to inspect the coil resistance,
output voltage and amperage.
YU-8036-B Inductive tachometer
YU-8036-B 90890-03113
90890-03113 Engine tachometer
This tool is needed for observing engine rpm.
YM-91042, 90890-04086 Clutch holding tool
YM-91042 90890-04086
This tool is used to hold the clutch when removing
or installing the clutch boss securing nut.
YM-34487 Dynamic spark tester
YM-34487 90890-06754
90890-06754 Ignition checker
This instrument is necessary for checking the igni-
tion system components.
ACC-QUICK-GS-KT Quick gasket
®ACC-QUICK-GS-KT 90890-85505
90890-85505 YAMAHA Bond No. 1215
This sealant (Bond) is used for crankcase mating
surface, etc.
5NX-9-30-1 6/5/01 3:53 PM Page 15

INSP
ADJ
3-13
TRANSMISSION OIL REPLACEMENT
3. Check:
9Transmission oil level
EC35K002
TRANSMISSION OIL REPLACEMENT
1. Start the engine and warm it up for several
minutes and wait for five minute.
2. Place the machine on a level place and hold
it on upright position by placing the suitable
stand under the engine.
3. Place a suitable container under the engine.
Transmission oil level checking steps:
9Remove the oil check bolt 1.
9Inspect the oil level.
NOTE:
Be sure the machine is positioned straight
up when inspecting the oil level.
w
Never attempt to remove the oil check bolt
just after high speed operation. The heat-
ed oil could spout out, causing danger.
Wait until the oil cools down.
Oil flows outOil level is correct.
Oil does not flow outOil level is low.
Add transmission
oil until oil flows
out.
9Inspect the gasket (oil check bolt), replace if
damaged.
9Tighten the oil check bolt.
Recommended oil:
Yamalube 4 (10W-30) or SAE
10W-30 type SE motor oil
Oil check bolt:
10 Nm (1.0 m•kg, 7.2 ft•lb)
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3-25
DRIVE CHAIN SLACK ADJUSTMENT
INSP
ADJ
EC36A060
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Check:
9Drive chain slack a
Above the seal guard installation bolt.
Out of specification Adjust
NOTE:
Before checking and/or adjusting, rotate the rear
wheel through several revolutions and check the
slack several times to find the tightest point. Check
and/or adjust chain slack with rear wheel in this
“tight chain” position.
Drive chain slack:
40~50 mm (1.6~2.0 in)
Drive chain lubricant:
SAE 10W-30 motor oil or suitable
chain lubricants
5. Install:
9Drive chain 1
9Joint 2
9Master link clip 3
cC
Be sure to install the master link clip to the
direction as shown.
aTurning direction
6. Lubricate:
9Drive chain
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5-36
CHASFRONT FORK
19. Wait ten minutes until the air bubbles have
been removed from the front fork, and the
oil has dispense evenly in system before
setting recommended oil level.
NOTE:
Fill with the fork oil up to the top end of the outer
tube, or the fork oil will not spread over to every
part of the front forks, thus making it impossible
to obtain the correct level.
Be sure to fill with the fork oil up to the top of the
outer tube and bleed the front forks.
20. Measure:
9Oil level (left and right) a
Out of specification  Adjust.
NOTE:
Be sure to install the spring guide 2when
checking the oil level.
w
Never fail to make the oil level adjustment
between the maximum and minimum level
and always adjust each front fork to the
same setting. Uneven adjustment can
cause poor handling and loss of stability.
Standard oil level:
135 mm (5.31 in)
Extent of adjustment:
80~150 mm (3.15~5.91 in)
From top of outer tube with
inner tube and damper rod
1 1
fully compressed without spring.
5NX-9-30-5B 6/7/01 2:05 PM Page 20

6-2
IGNITION SYSTEMELEC
EC620000
IGNITION SYSTEM
EC621002
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to
ignition system failure and for checking the spark plug which will not spark.
*Clean or replace
spark plug.
Primary coil
Secondary coil
Repair or replace.
Spark
Check entire ignition
system for connection.
Spark gap test
No good
No good
No good
No good
No good
No good No Spark
Check “ENGINE STOP”
button.
Pick-up coil
Source coil
Check ignition coil.
Check CDI magneto.
Replace CDI unit.
Replace.
Replace.
Replace.
Replace.
Replace.
*marked: Only when the ignition checker is used.
NOTE:
9Remove the following parts before inspection.
1) Seat
2) Fuel tank
9Use the following special tools in this inspection.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754Pocket tester:
YU-3112-C/90890-03112
OK
OK
OK
OK
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7-12
SETTINGTUN
EC71M001
Change of the heat range of spark plugs
Judging from the discoloration of spark plugs, if
they are found improper, it can be corrected by
the following two methods; changing carburetor
settings and changing the heat range of spark
plug.
9In principle, it is advisable to first use spark
plugs of standard heat range, and judging from
the discoloration of spark plugs, adjust carbure-
tor settings.
9If the calibration No. of the main jet must be
changed by ±30, it is advisable to change the
heat range of spark plugs and newly select the
proper main jet.
NOTE:
9When checking the discoloration of spark
plugs, be sure to stop the engine immediately
after a run and check.
9Avoid racing.
9When changing the heat range of spark plugs,
never attempt to change it more than ±1 rank.
9When using spark plugs other than standard,
make sure of the difference in heat range and
find the equivalent to the standard.
9Note that even if the discoloration seems prop-
er, it may slightly vary with the spark plug
maker and oil in use.
Standard spark plug BR8EG/NGK
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