Kawasaki Ninja Service Manual: Valve Seat Inspection

Kawasaki Ninja Service Manual / Engine Top End / Valves / Valve Seat Inspection

Measure the outside diameter [D] of the seating pattern on the valve seat.

If the outside diameter is too large or too small, repair the seat (see Valve Seat Repair).

Valve Seating Surface Outside Diameter Standard:

Exhaust 23.9 24.1 mm (0.941
0.949 in.)


Intake 30.4 30.6 mm (1.197
1.205 in.)


Valve Seat Inspection


Measure the seat width [E] of the portion where there is no build-up carbon (white portion) of the valve seat with a vernier caliper.

Good [F]

If the width is too wide [G], too narrow [H] or uneven [J], repair the seat (see Valve Seat Repair).

Valve Seating Surface Width Standard:

Exhaust 0.8 1.2 mm (0.03
0.05 in.)


Intake 0.5 1.0 mm (0.02
0.04 in.)


Valve-to-Guide Clearance Measurement (Wobble Method)
If a small bore gauge is not available, inspect the valve guide wear by measuring the valve to valve guide clearance with the wobble method as indicated below. Insert a new valve [A] into the gu ...

Valve Seat Repair
Repair the valve seat with the valve seat cutters [A]. Special Tools - Valve Seat Cutter Holder Bar [B]: 57001 -1128 Valve Seat Cutter Holder, 4.5 [C]: 57001 -1330 [For Exhaust Valve Seat] V ...

Other materials:

Balance Inspection
Remove the front and rear wheels (see Front/Rear Wheel Removal). Support the wheel so that it can be spun freely. Spin the wheel lightly, and mark [A] the wheel at the top when the wheel stops. Repeat this procedure several times. If the wheel stops of its own accord in various positi ...

Rear Sprocket Removal
Remove the rear wheel (see Rear Wheel Removal in the Wheels/Tires chapter). NOTICE Do not lay the wheel on the ground with the disc facing down. This can damage or warp the disc. Place blocks under the wheel so that the disc does not touch the ground. Remove: Rear Sprocket Nu ...

Nozzle Assy Installation
Replace the dust seals [A] with new ones. Apply engine oil to the new dust seals, and install them. Install the nozzle assy securely. Push the four mounting positions of the injectors. Set the joint pipe parallel to the air cleaner housing [B]. NOTICE When installing the nozzle assy, ap ...