Yamaha YZF-R125 Owners Manual: Brake pedal

Brake lever

Brake lever Brake lever The brake lever is located at the right handlebar grip. To apply the front brake, pull the lever toward the handlebar grip. ...

Fuel tank cap

Fuel tank cap Fuel tank cap lock cover Unlock. To remove the fuel tank cap Open the fuel tank cap lock cover. Insert the key into the lock and turn it 1/4 turn counterclockwise. ...

Other materials:

Checking the cylinder head
1. Eliminate: Combustion chamber carbon deposits (with a rounded scraper) NOTE: Do not use a sharp instrument to avoid damaging or scratching: Spark plug bore threads Valve seats 2. Check: Cylinder head Damage/scratches   Replace. Cylinder head water jacket Min ...

Starting failures
Engine 1. Cylinder and cylinder head - Loose spark plug - Loose cylinder head or cylinder - Damaged cylinder head gasket - Damaged cylinder gasket - Worn or damaged cylinder - Incorrect valve clearance - Improperly sealed valve - Incorrect valve-to-valve-seat contact - Incorrect valve timi ...

Checking the piston rings
1. Measure: Piston ring side clearance Out of specification Replace the piston and piston rings as a set. NOTE: Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and piston rings. 2. Install: Piston ring (into the cylind ...