Honda GP160H, Руководство пользователя

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12-9
dummyhead dummyhead
CYLINDER HEAD
VALVE SEAT RECONDITIONING
Inspect the valve seat contact area (page 12-6).
Using a 45° seat cutter, remove any roughness or
irregularities from the seat.
If the contact area is too low on the valve, the seat must
be raised using a 60° interior cutter.
If the contact area is too high on the valve, the seat
must be lowered using a 32° flat cutter.
Valve seat cutters [1]/grinder or equivalent valve seat
refacing equipment is recommended to correct a worn
valve seat.
• Turn the cutter clockwise, never counterclockwise.
• Continue to turn the cutter as you lift it from the valve
seat.
Make a light pass with the 45° cutter to remove any
possible burrs at the edge of the seat.
Be sure that the width of the finished valve seat is within
specification.
Lap the valves into their seats, using a commercially
available valve lapper and lapping compound.
After lapping, wash all residual compound off the
cylinder head and valve.
• Do not push the valve against the seat with force
during lapping. Apply a light pass with the valve
lapper.
• Avoid lapping the valve in the same position as it
causes uneven wear. Lap the valve by turning the
lapper slowly.
• Take care not to allow the lapping compound to
enter the gap between the stem and guide.
45°
60°
32°
TOO LOW
TOO HIGH
TOOLS:
Cutter holder, 5.5 mm [2]
07781-0010101
Seat cutter, 27.5 mm (45° IN) 07780-0010200
Seat cutter, 24.5 mm (45° EX) 07780-0010100
Flat cutter, 28 mm (32° IN) 07780-0012100
Flat cutter, 24 mm (32° EX) 07780-0012500
Interior cutter, 26 mm (60° IN) 07780-0014500
Interior cutter, 22 mm (60° EX) 07780-0014202
[1]
[2]
STANDARD: 0.70 – 0.90 mm (0.028 – 0.035 in)
45°
VALVE LAPPER
(Commercially available)