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:

Checking the front fork
1. Stand the vehicle on a level surface. WARNINGSecurely support the vehicle so that there is no danger of it falling over. 2. Check: Inner tube Damage/scratches Replace. Oil seal Oil leakage Replace. 3. Hold the vehicle upright and apply the front brake. 4. Che ...

Faulty clutch
Clutch slips 1. Clutch Improperly assembled clutch Improperly adjusted clutch cable Loose or fatigued clutch spring Worn friction plate Worn clutch plate 2. Engine oil Incorrect oil level Incorrect oil viscosity (low) Deteriorated oil Clutch drags 1. Clutch Unevenly t ...

Engine break-in
There is never a more important period in the life of your engine than the period between 0 and 1000 km (600 mi). For this reason, you should read the following material carefully. Since the engine is brand new, do not put an excessive load on it for the first 1000 km (600 mi). The vari ...