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:

Check 2-1: Speedometer Inspection
Using the suitable stand, raise the rear wheel off the ground. Rotate the rear wheel by hand or start the engine. Check that the display changes speedometer. If the display function does not work, check the following parts. Rear Wheel Rotation Sensor (see Wheel Rotation Sensor Inspe ...

Spring Plate Free Play Measurement
Insufficient clutch free play will cause the engine braking effect to be more sudden, resulting in rear wheel hop. On the other hand, if the free play is excessive, the clutch lever may feel “spongy” or pulsate when pulled. Hold an extra drive shaft in a vise and install the following c ...

Ignition System
WARNINGThe ignition system produces extremely high voltage. Do not touch the spark plug, ignition coil or ignition coil lead while the engine is running, or you could receive a severe electrical shock. NOTICE Do not disconnect the battery cables or any other electrical ...