Yamaha YZF-R125 Service Manual: Throttle body

Checking the fuel pressure

1. Check: Pressure regulator operation a. Remove the fuel hose connector cover "1" and disconnect the fuel hose "2" from the fuel pump. CAUTION:Although the fuel has been removed from ...

Removing the throttle body

1. Extract the fuel in the fuel tank through the fuel tank filler hole with a pump. 2. Disconnect: Fuel hose WARNINGCover the fuel hose connections with a cloth when disconnecti ...

Other materials:

Removing the primary drive gear and balancer gears
1. Loosen: Primary drive gear nut "1" NOTE: Place the aluminum plate "a" between the balancer drive gear "2" and the balancer driven gear "3", and then loosen the primary drive gear nut. 2. Straighten the lock washer tab. 3. Loosen: Balancer driven gear nut "1" NOTE: Place ...

Adjusting the valve clearance
The following procedure applies to all of the valves. NOTE: Valve clearance adjustment should be made on a cold engine, at room temperature. When the valve clearance is to be measured or adjusted, the piston must be at top dead center (TDC) on the compression stroke. 1. Remove: ...

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 ...