Yamaha YZF-R125 Service Manual: Water pump

Installing the thermostat

1. Install: Thermostat NOTE: Install the thermostat with its breather hole "a" facing up. 2. Install: Copper washer Coolant temperature sensor CAUTION:Use extreme care when ...

Disassembling the water pump

1. Remove: Water pump seal "1" NOTE: Remove the water pump seal from the inside of the water pump housing "2". 2. Remove: Bearing "1" NOTE: Remove the bearing from the outside of ...

Other materials:

Checking the valve seats
The following procedure applies to all of the valves and valve seats. 1. Eliminate: Carbon deposits (from the valve face and valve seat) 2. Check: Valve seat Pitting/wear Replace the cylinder head. 3. Measure: Valve seat width C "a" Out of specification Replace the ...

Installing the piston and cylinder
1. Install: Top ring "1" 2nd ring "2" Oil ring expander "3" Lower oil ring rail "4" Upper oil ring rail "5" NOTE: Be sure to install the piston rings so that the manufacturer marks or numbers face up. 2. Install: Piston "1" Piston pin "2" Piston pin clips "3" NOTE: ...

Checking the camshaft
1. Check: Camshaft lobes Blue discoloration/pitting/scratches  Replace the camshaft. 2. Measure: Camshaft lobe dimensions "a" and "b" Out of specification Replace the camshaft. 3. Check: Camshaft oil passage Obstruction Blow out with compressed air. ...