Parsun F40 EFI, Maintenance Manual

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Valve guide inner diameter: 5.50
～
5.518mm
Note:
Do not rotate the reamer counterclockwise when taking it out.
Check valve seat ring
1. Remove carbon deposit from the valve.
2. Coat a thin layer of dye evenly on the sealing surface of the valve seat ring.
3. Grind the valve on the valve seat with the valve grinding tool.
4. Measure the width of valve sealing surface.
Dye will stick to the valve sealing surface.
If the valve and valve seat ring fit incorrectly or the sealing surface width does not
meet the specified value, trim the valve seat.
If the contact surface is uneven, replace the valve guide.
Width of intake and exhaust valve sealing surface: 0.9
～
1.1mm
Trim the valve seat ring
1. Trim the valve with a 45° valve seat ring cutter and adjust the width of the sealing
surface.
Turn the cutter clockwise until the surface of the seat ring is smooth.
2. If the valve sealing surface is too wide and in the middle of the valve surface, trim the
top edge of the seat ring with a 30° cutter and trim the bottom edge of the seat ring
with a 60° cutter, and adjust the width of the sealing surface.
3. If the valve sealing surface is too narrow and at the top edge of the valve surface, trim
the top edge of the seat ring with a 30° cutter, and adjust the width of the sealing surface
with a 45° tool (if any).
4. If the valve sealing surface is too narrow and at the bottom edge of the valve surface,
trim the bottom edge of the seat ring with a 60° cutter, and adjust the width of the sealing
surface with a 45° cutter (if any).
5. Apply a thin layer of abrasive evenly to the valve seat ring, and grind the valve with a