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 Fork Inspection
Holding the brake lever, pump the front fork up and down several times to inspect smooth stroke. Visually inspect the front fork for oil leakage, scoring or scratches on the outer surface of the inner tube. If any doubt about the front fork, it should be checked by an authorized K ...

Brake Pad Wear Inspection
Remove the brake pads (see Front/Rear Brake Pad Removal in the Brakes chapter). Check the lining thickness [A] of the pads in each caliper. If the lining thickness of either pad is less than the service limit [B], replace both pads in the caliper as a set. Front Brake Pad [C] Rea ...

Fuels Containing Oxygenates
Gasoline frequently contains oxygenates (alcohols and ethers) especially in areas of the U.S. and Canada which are required to sell such reformulated fuels as part of a strategy to reduce exhaust emissions. The types and volume of fuel oxygenates approved for use in unleaded gasoline by th ...