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 Communication Error (Service Code 39)
ECU Communication Line Inspection When the data is not sent from the ECU to the meter unit for more than about 10 seconds, the service code 39 is displayed. The data is sent through the CAN communication line. The service code 39 is detected with the meter unit. When the user mode, this commun ...

Valve Clearance
Valve and valve seat wear decreases valve clearance, upsetting valve timing. NOTICE If valve clearance is left unadjusted, wear will eventually cause the valves to remain partly open; which lowers performance, burns the valves and valve seats, and may cause serious engine damage. Valve cle ...

Shift Fork Guide Pin/Drum Groove Wear Inspection
Measure the diameter of each shift fork guide pin [A], and measure the width [B] of each shift drum groove. If the guide pin on any shift fork is less than the service limit, the fork must be replaced. Shift Fork Guide Pin Diameter Standard: 6.9 7.0 mm (0.272 0.276 in.) Service Limit: ...