Contents: Removal ⇓ Examination ⇓
Removal
1. Using a special tool to compress valve springs (09222-28000, 09222-28100), remove the cracker. Next, remove the upper valve spring plate, valve spring, lower plate and valve.
Note: Keep all parts in the order in which they should be installed in their original locations.
2. Use pliers to remove the sealing cap. Do not reuse it.
Examination
Valves
1. Using a wire brush, thoroughly clean the valve.
2. Check each valve for wear, damage and destruction of the head and stem in area B. Repair or correct if necessary.
If the end A of the rod is worn, restore its surface if necessary. This direction should be minimal. Also restore the surface of the valve working chamfer. If the valve plate height is less than the permissible limit, replace the valve.
Valve springs
1. Check the length of the spring in the assembled state and its extension. If it exceeds the permissible limits, replace the spring.
2. Check the parallelism of the ends of each spring. If it exceeds the established limits, replace the spring.
Valve springs:
- Height - 21.6 kg/35 mm
- Load capacity - 45.1 kg/27.2 mm
- Deviation from parallelism of the ends is 1.5° or less
Valve bushings
Check the clearance between the valve stem and the bushing. If it exceeds the specified limits, replace the valve bushing with the next size bushing.
Clearance between valve stem and sleeve.
Nominal size:
- Inlet valve - 0.03-0.06 mm
- Exhaust valve - 0.05-0.08 mm
Maximum size:
- Inlet valve - 0.1 mm
- Exhaust valve - 0.15 mm
Valve seat
Check the valve seat for signs of overheating and proper contact with the valve seat face. Repair or replace the valve seat if necessary. Before repairing the seat, check the valve bushing for wear. If the bushing is worn, replace it and then repair the seat. Repair the valve seat using a valve seat grinder or a milling cutter.
Valve seat replacement procedure
1. The valve seat worn beyond the permissible limits should be replaced at normal temperature after cutting off most of the seat wall with a valve seat grinder as shown in the figure.
2. After removing the seat, use a reamer or milling cutter to process the hole for the seat. Process to the size specified in the table.
3. Heat the cylinder head to about 250°C and press in the oversized seat. The oversized seat should be at normal room temperature before installation. After installing the new seat, treat its surface. Valve Bushing Replacement Procedure.
The procedure for replacing the valve sleeve and installing the valves is the same as for engines with one camshaft (see the relevant section above in this chapter).