Service manual

Page 49 of 151

• Use a 60° cutter to cut the quarter lower parts out.

• Remove the cutter and check the new valve seat.

• Use a 45° cutter to grind the valve seat to the

specified standard width.

• Make sure that all roughness and uneven faces

have been ground.

• Grind the valve seat again if necessary.

• Coat the valve seat surface with red paint.

• Install the valve through valve guide until the

valve touches the valve seat.

• Slightly press down the valve but do not rotate

it so that a seal track will be created on the

contact surface.

• The contact surfaces of the valve and valve seat

are very important to the valve sealing capacity.

• If the contact surface is too high, grind the valve

seat with a 32° cutter. Then, grind the valve seat to

the specified width.

• If the contact surface is too low, grind the valve

seat with a 60° cutter. Then, grind the valve seat to

the specified width.