Check and repair the valve seat

Measure the width of the contact surface of the valve seat. If necessary, treat the seat or a valve plate, using a suitable device (Fig. 2.147).

Standard width: 1.2-1.6 mm.

Check the alignment of the contact surface relative to the valve seat (Fig. 2.148).

If the contact surface is offset outwards, process valve seat cutting tool with a working angle of 70 ?� (inlet) or 65 ?� (release) and the cutting tool with an angle of 45 ?�.

If the contact surface is shifted inward treat the valve seat cutting tool with a working angle of 30 ?� (inlet) or 0 ?� (release) and the cutting tool with an angle of 45 ?�.

Check the penetration of the valve seat. Measure the protrusion (Size L) of the valve stem (Fig. 2.149).

If the measured height is not correct, replace the cylinder head.

Standard size L:

Inlet: 40,64-42,24 mm;

Release: 40,50-42,10 mm.