Yamaha YZF-R125 Service Manual: Crankcase

Installing the primary drive gear and balancer gears

1. Install: Balancer driven gear "1" Lock washer Balancer drive gear "2" Primary drive gear Washer "3" Balancer driven gear nut Primary drive gear nut NOTE: Align the punch mar ...

Separating the crankcase

1. Remove: Crankcase bolts NOTE: Loosen each bolt 1/4 of a turn at a time, in stages and in the proper sequence as shown. A. Right crankcase B. Left crankcase 2. Turn: Shift drum s ...

Other materials:

Engine specifications
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Engine oil and oil filter element
The engine oil level should be checked before each ride. In addition, the oil must be changed and the oil filter element replaced at the intervals specified in the periodic maintenance and lubrication chart. To check the engine oil level Place the vehicle on a level surface and hol ...

Installing the piston and cylinder
1. Install: Top ring "1" 2nd ring "2" Oil ring expander "3" Lower oil ring rail "4" Upper oil ring rail "5" NOTE: Be sure to install the piston rings so that the manufacturer marks or numbers face up. 2. Install: Piston "1" Piston pin "2" Piston pin clips "3" NOTE: ...