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:

Front, Rear Wheel Rotation Difference Abnormal Inspection (Service Code b 25)
Check the following and correct the faulty part. Incorrect Tire Pressure Tires not recommended for the motorcycle were installed (incorrect tire size). Deformation of Wheel or Tire Missing Teeth or Clogging with Foreign Matter of Sensor Rotor (see Wheel Rotation Sensor Rotor Inspe ...

Radiator Cap Inspection
Remove: Radiator Cap (see Coolant Change in the Periodic Maintenance chapter) Check the condition of the bottom [A] and top [B] valve seals and valve spring [C]. If any one of them shows visible damage, replace the cap with a new one. Install the cap [A] on a cooling system pr ...

System Components
1. KIBS ECU With input from the front and rear wheel sensors and front caliper hydraulic pressure, the KIBS ECU analyzes various conditions on the motorcycle, and with additional information from the FI ECU (engine speed, throttle position, gear position, and clutch actuation) precisely control ...