Service Manual — page 282 of 715

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5-32 ENGINE TOP END
Valves
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 guide [B] and set a dial
  gauge against the stem perpendicular to it as close as
  possible to the cylinder head mating surface.
• Move the stem back and forth [C] to measure valve/valve
  guide clearance.
• Repeat the measurement in a direction at a right angle to
  the first.
  If the reading exceeds the service limit, replace the guide.
                              NOTE
    ○The reading is not actual valve/valve guide clearance
      because the measuring point is above the guide.

    Valve/Valve Guide Clearance (Wobble Method)
      Standard:
        Exhaust        0.08 ∼ 0.16 mm (0.0031 ∼ 0.0063 in.)
        Intake         0.03 ∼ 0.10 mm (0.0012 ∼ 0.0039 in.)
      Service Limit:
        Exhaust        0.35 mm (0.014 in.)
        Intake         0.30 mm (0.012 in.)

Valve Seat Inspection
• Remove  the valve (see Valve Removal).
• and valve seat
  Check the valve seating surface [A] between the valve [B]
                 [C].
○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 Seat Repair).
    Valve Seating Surface Outside Diameter
      Standard:
        Exhaust        24.7 ∼ 24.9 mm (0.972 ∼ 0.980 in.)
        Intake         28.9 ∼ 29.1 mm (1.138 ∼ 1.146 in.)
○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 (0.031 ∼ 0.047 in.)
        Intake         0.5 ∼ 1.0 mm (0.020 ∼ 0.039 in.)