Yamaha YZF-R125 Service Manual: Checking the crankshaft

Yamaha YZF-R125 Service Manual / Engine / Crankshaft / Checking the crankshaft

1. Measure:

Crankshaft runout Out of specification Replace
the crankshaft, bearing or both.

NOTE:

Turn the crankshaft slowly.

Checking the crankshaft

2. Measure:

Big end side clearance Out of specification Replace
the crankshaft.

3. Measure:

Crankshaft width Out of specification
Replace the crankshaft.

3. Measure:

Crankshaft width Out of specification Replace the crankshaft.

4. Check:

Crankshaft sprocket Damage/wear Replace the
crankshaft.
Bearing Cracks/damage/wear Replace the
crankshaft.

5. Check:

Crankshaft journal Scratches/wear Replace the
crankshaft.
Crankshaft journal oil passage Obstruction Blow out with
compressed air.

Removing the crankshaft

1. Remove: Crankshaft "1" NOTE: Remove the crankshaft with the crankcase separating tool "2". Make sure the crankcase separating tool is centered over the crankshaft. CAUTIO ...

Installing the crankshaft

1. Install: Crankshaft "1" NOTE: Install the crankshaft with the crankshaft installer pot "2", crankshaft installer bolt "3", adapter (M12) "4" and spacer (crankshaft installer) "5". ...

Other materials:

Checking the ignition spark gap
1. Check: Ignition spark gap Out of specification Perform the ignition system troubleshooting, starting with step 5. Refer to "TROUBLESHOOTING" on page 8-3. NOTE: If the ignition spark gap is within specification, the ignition system circuit is operating normally. a. Disconnect the spa ...

Checking the timing chain tensioner
1. Check: Timing chain tensioner Cracks/damage/rough movement Replace. a. Lightly press the timing chain tensioner rod into the timing chain tensioner housing by hand. NOTE: While pressing the timing chain tensioner rod, wind it clockwise with a thin screwdriver "1" until it stops. b. ...

Checking the rear brake caliper
1. Check: Brake caliper piston "1" Rust/scratches/wear Replace the brake caliper piston. Brake caliper cylinder "2" Scratches/wear Replace the brake caliper assembly. Brake caliper body "3" Cracks/damage Replace the brake caliper assembly. Brake fluid deli ...