Yamaha YZF-R125 Service Manual: Checking the drive chain

Yamaha YZF-R125 Service Manual / Chassis / Chain drive / Checking the drive chain

1. Measure:

15-link section "a" of the drive chain Out of specification Replace the drive chain.

a. Measure the length "a" between the inner sides of the pins and the length "b" between the outer sides of the pins on a 15-link section of the drive chain as shown in the illustration.

Checking the drive chain

b. Calculate the length "c" of the 15-link section of the drive chain using the following formula.

Drive chain 15-link section length "c" = (length "a" between pin inner sides + length "b" between pin outer sides)/2

NOTE:

When measuring a 15-link section of the drive chain, make sure that the drive chain is taut.
Perform this procedure 2-3 times, at a different location each time.

Checking the drive chain

2. Clean:

Drive chain

a. Wipe the drive chain with a clean cloth.

b. Put the drive chain in kerosene and remove any remaining dirt.

c. Remove the drive chain from the kerosene and completely dry it.

CAUTION:

This motorcycle has a drive chain with small rubber O-rings "1" between the drive chain side plates. Never use high-pressure water or air, steam, gasoline, certain solvents (e.g., benzine), or a coarse brush to clean the drive chain. High-pressure methods could force dirt or water into the drive chain's internals, and solvents will deteriorate the O-rings. A coarse brush can also damage the O-rings. Therefore, use only kerosene to clean the drive chain.
Do not soak the drive chain in kerosene for more than ten minutes, otherwise the Orings can be damaged.

Checking the drive chain

3. Check:

O-rings "1" Damage Replace the drive
chain.
Drive chain rollers "2" Damage/wear Replace the
drive chain.
Drive chain side plates "3" Damage/wear Replace the drive
chain.

Cracks Replace the drive
chain.

Checking the drive chain

4. Lubricate:

Drive chain

Chain drive

Removing the drive chain 1. Stand the vehicle on a level surface. WARNINGSecurely support the vehicle so that there is no danger of it falling over. NOTE: Place the vehicle on ...

Checking the drive sprocket

1. Check: Drive sprocket More than 1/4 tooth "a" wear Replace the drive chain sprockets as a set. Bent teeth Replace the drive chain sprockets as a set. b. Correct 1. Dri ...

Other materials:

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 ...

General maintenance and lubrication chart
TIP The air filter needs more frequent service if you are riding in unusually wet or dusty areas. Hydraulic brake service Regularly check and, if necessary, correct the brake fluid level. Every two years change the brake fluid. Replace the brake hoses every four ye ...

Checking the clutch springs
The following procedure applies to all of the clutch springs. 1. Check: Clutch spring Damage Replace the clutch springs as a set. 2. Measure: Clutch spring free length "a" Out of specification Replace the clutch springs as a set. ...