Removal
1. Using a special tool to compress the valve springs (09222-28000, 09222-28100), remove the cracker. Next, remove the upper valve spring plate, valve spring, lower plate and valve.
Note: Keep these dividers in the order in which they should be installed in their original places.
2. Use pliers to remove the sealing cap (do not reuse it).
Examination
Valves
Check each valve for wear, damage, head destruction and stem in zone B. Repair or correct if necessary. If end A of the stem is worn, restore its surface. This direction should be minimal. Also restore the surface of the valve working chamfer. If the valve edge 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 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.
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, then repair the seat. Repair the valve seat using a valve seat grinder or a milling cutter.
Valve seat replacement procedure
1. A valve seat that is worn beyond the permissible limits should be replaced after cutting off most of the seat wall using 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 approximately 250°C and press in an oversized seat.
Valve Bushing Replacement Procedure
The valve sleeve is installed using a press fit. Using a valve sleeve installation device. (09221-22000) or using the appropriate tool, replace the valve sleeve in the following order:
1. Using the valve sleeve installer pusher, push the valve sleeve towards the cylinder block using a press.
2. Machine the valve bushing hole in the cylinder head to the increased size of the new valve bushing.
3. Using a valve guide installer or appropriate tool, press the valve guide into a press fit. Using a valve guide installer, it is possible to press the valve guide to a specified height. The valve guide must be installed from the top of the cylinder head. Note that the intake and exhaust guides have different lengths (42.7 mm for the intake valve and 39.1 mm for the exhaust valve).
The oversized saddle should be at normal room temperature before installation. After installing the new saddle, treat its surface as just described above.
4. After installing the valve bushings, insert new valves into them and check the clearance between them.
5. Each time the valve bushings are replaced, check the nature of the valve contact with the seat and, if necessary, restore the seat surface.
Installation
Note:
1) Clean all parts before assembly.
2) Use engine oil to lubricate rotating and sliding parts.
1. After installing the lower spring plate, press the sealing cap onto the valve sleeve. To install it, push the cap on by gently rotating the valve sealing cap installer (09222-22000).
The sealing cap is installed in the desired position using a special tool. If the sealing cap is not positioned correctly, the lug and its internal hole may be eccentric and oil may leak into the valve sleeve. Do not rotate the cap when installing. Do not use old sealing caps.
2. Apply engine oil to each valve. Insert the valves into the bushings without forcing the valve stem through the sealing cap. After installation, check that the valve moves easily.
3. Install the valve springs and their upper retainers. The valve springs should be installed with the varnished side facing the upper retainer.
4. Using a valve spring compressor (09222-28000; 09222-28100), compress the spring. Be careful not to deform the top of the plate with the sealing cap. Then install the crackers. After installing the valves, make sure the crackers are installed correctly.
5. Install the cylinder head.