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:

ECU Removal
NOTICE Never drop the ECU especially on a hard surface. Such a shock to the ECU can damage it. Remove the upper air cleaner housing (see Air Cleaner Element Replacement in the Periodic Maintenance chapter). Lift up the ECU [A] with rubber protector [B] to disconnect the connectors [C]. ...

Air Switching Valve (Service Code 64)
Air Switching Valve Removal/Installation Refer to the Air Switching Valve Removal/Installation in the Engine Top End chapter. Air Switching Valve Inspection Refer to the Air Switching Valve Unit Test in the Electrical System chapter. If the air switching valve [A] is normal, check ...

Spring Preload Adjustment
Remove the rear shock absorber from the frame (see Rear Shock Absorber Removal). Loosen the locknut and turn out the adjusting nut to free the spring. Special Tools - Hook Wrench T=3.2 R37: 57001-1539 Hook Wrench R=35: 57001-1580 To adjust the spring preload, turn in the adjusting n ...