Yamaha YZF-R125 Service Manual: Engine
- Engine removal
- Cylinder head
- Removing the cylinder head
- Checking the cylinder head
- Checking the camshaft sprocket and timing chain guide
- Checking the timing chain tensioner
- Checking the decompression system
- Installing the cylinder head
- Camshaft
- Checking the camshaft
- Checking the rocker arms and rocker arm shafts
- Installing the camshaft and rocker arms
- Valves and valve springs
- Removing the valves
- Checking the valves and valve guides
- Checking the valve seats
- Checking the valve springs
- Installing the valves
- Cylinder and piston
- Removing the piston
- Checking the cylinder and piston
- Checking the piston rings
- Checking the piston pin
- Installing the piston and cylinder
- Generator and starter clutch
- Removing the generator
- Removing the starter clutch
- Checking the starter clutch
- Installing the starter clutch
- Installing the generator
- Electric starter
- Clutch
- Removing the clutch
- Checking the friction plates
- Checking the clutch plates
- Checking the clutch springs
- Checking the clutch housing
- Checking the clutch boss
- Checking the primary drive gear
- Checking the primary driven gear
- Installing the clutch
- Oil pump
- Shift shaft
- Balancer gear
- Removing the primary drive gear and balancer gears
- Checking the balancer gears and primary drive gear
- Installing the primary drive gear and balancer gears
- Crankcase
- Separating the crankcase
- Checking the crankcase
- Checking the timing chain and timing chain guide
- Checking the bearings and oil seal
- Installing the bearing retainer
- Assembling the crankcase
- Crankshaft
- Transmission
Installing the drive chain
1. Lubricate:
Drive chain
Master link
2. Install:
Drive sprocket
Drive sprocket retainer bolts
3. Install:
Master link
O-rings
Master link plate
Master link clip "1"
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Engine removal
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Other materials:
Checking the shift drum assembly
1. Check:
Shift drum groove
Damage/scratches/wear Replace
the shift
drum assembly.
Shift drum segment "1"
Damage/wear Replace the
shift drum assembly.
Shift drum bearing "2"
Damage/pitting Replace the
shift drum assembly.
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Circuit diagram
4. Main fuse
5. Main switch
9. Battery
14.Neutral switch
25.ECU (engine control unit)
31.Fuel sender
34.Rear brake light switch
35.Front brake light switch
37.Tail/brake light
38.Rear right turn signal light
39.Rear left turn signal light
40.Front right turn signal light
41.Front lef ...
Troubleshooting
The starter motor fails to turn.
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Left lower side cowling
4. Left upper side cowling
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