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:

Incorrect engine idling speed
Engine 1. Cylinder and cylinder head Incorrect valve clearance Damaged valve train components 2. Air filter Clogged air filter element Fuel system 1. Throttle body Damaged or loose throttle body joint Improperly adjusted engine idling speed (idle adjusting screw) Improper ...

Checking the rear shock absorber assembly
1. Check: Rear shock absorber rod Bends/damage Replace the rear shock absorber assembly. Rear shock absorber Oil leaks Replace the rear shock absorber assembly. Spring Damage/wear   Replace the rear shock absorber assembly. Bushing Damage/wear Replace the rea ...

Air induction system
1. Air induction system hose (air filter case to reed valve assembly) 2. Air induction system reed valve assembly 3. Air induction system hose (reed valve assembly to exhaust pipe) Checking the air induction system Air injection The air induction system burns unburned exhaust gases b ...