Honda Crf250l Service Manual

MEMO
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14-1
14
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14. CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
SERVICE INFORMATION ···························14-2
TROUBLESHOOTING·································14-2
COMPONENT LOCATION ··························14-3
CRANKCASE SEPARATION··················\
····14-4
CRANKSHAFT ··················\
··················\
········14-6 MAIN JOURNAL BEARING ··················\
······ 14-7
TRANSMISSION ······································· 14-10
BALANCER··············································· 14-14...

14-2
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCERSERVICE INFORMATION
GENERAL
 • This section covers crankcase separation for service of the crankshaft, transmission and balancer.
 • The crankcase must be separated to service the crankshaft, ba lancer and transmission. To service these parts, the engine must
be removed from the frame.
 • The following components must be removed before separating the crankcase.
– Camshaft (page 10-6)
– Cylinder...

14-3
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
COMPONENT LOCATION
10 N·m (1.0 kgf·m, 7 lbf·ft)
44 N·m (4.5 kgf·m, 32 lbf·ft) 

14-4
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
CRANKCASE SEPARATION
Refer to Service Information (page 14-2) for removal of
necessary parts before di sassembling the crankcase.
Remove the tensioner pivot bolt [1], collar [2] and cam
chain tensioner [3].
Remove the cam chain [4] and timing sprocket [5].
Check the cam chain tensio ner [1] for excessive wear
or damage, replace it if necessary.
Install a 3 mm (0.12 in) O.D. pin [1] into the hole [2] of
the balancer driven gear assembly...

14-5
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
Remove the woodruff key [1] from the balancer shaft.
Loosen the crankcase bolts [1] in a crisscross pattern in
2 or 3 steps, and remove the bolts.
Place the crankcase assembly with the right crankcase
down.
Carefully separate the left  crankcase [1] from the right
crankcase [2] while tapping them at several locations
with a plastic hammer.
Remove the dowel pins [1] and O-ring [2].[1]
[1]
Do not pry the
crankcase halves
with a...

14-6
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
CRANKSHAFT
REMOVAL
Separate the crankcase halves (page 14-4).
Remove the crankshaft [1] from the right crankcase.
INSPECTION
Inspect the following parts for scratch, damage,
abnormal wear and deformation. Replace if necessary.
– Crankshaft
– Connecting rod
– Timing sprocket
Measure each part according to CRANKCASE/
CRANKSHAFT/TRANSMISSION BALANCER
SPECIFICATIONS (page 1-7).
Replace any part if it is out of service limit.
CRANKSHAFT...

14-7
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
MAIN JOURNAL BEARING
BEARING INSPECTION
Remove the following:
– Crankshaft (page 14-6)
– Transmission (page 14-10)
– Balancer shaft (page 14-14)
Clean off any oil from the bearings.
Check the main journal bearings [1] for unusual wear,
damage or peeling and replace them if necessary.
MAIN JOURNAL OIL CLEARANCE
Measure and record the main journal bearing I.D. at
between the bearing groove and crankcase outside end
of the bearing, and 90...

14-8
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
Measure and record the crankcase main journal
bearing support I.D. at 90 degrees to the index mark [1].
Depending upon the results of the above
measurements there are four possible scenarios for
main journal bearing selection:
 • Crankshaft and crankcase are replaced
 • Crankcase only is replaced
 • Crankshaft only is replaced
 • Main journal bearings only are replaced
Carefully refer to the following instructions and tables
for main...

14-9
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CRANKCASE/CRANKSHAFT/TRANSMISSION/BALANCER
BEARING INSTALLATION
Apply engine oil to new bearing [1] surface.
Set new bearings to the metal installer as shown.
Tighten the bolts [2] alternately in several steps.
Set the bearings [1] and special tools assembly on
inside of the crankcase, fitting the bearing edge in the
crankcase main journal.
Align the mating line of the bearings with the index mark
[2] on the crankcase as shown.
Set the crankcase and special tools on the...