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:

Brake Fluid Level Inspection
Check that the brake fluid level in the front brake reservoir [A] is above the lower level line [B]. NOTE Hold the reservoir horizontal by turning the handlebar when checking brake fluid level. If the fluid level is lower than the lower level line, fill the reservoir to the upper lev ...

Fuel Pump Operating Voltage Inspection
NOTE Be sure the battery is fully charged. Turn the ignition switch to OFF. Remove: Fuel Tank Bolts (see Fuel Tank Removal) Fuel Tank Bracket Bolts (see Fuel Tank Removal) Disconnect the fuel pump lead connector and connect the harness adapter [A] between these connectors as shown i ...

Piston Removal
Remove: Crankshaft (see Crankshaft Removal) Remove the piston together with the connecting rod to the cylinder head side. NOTICE Discard the connecting rod bolts and nuts. To prevent damage to the crankpin surfaces, do not allow the connecting rod bolts to bump against the crankpins. ...